JP4098114B2

JP4098114B2 - Disk molding die and disk manufacturing method

Info

Publication number: JP4098114B2
Application number: JP2003046405A
Authority: JP
Inventors: 和夫井上
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2003-02-24
Filing date: 2003-02-24
Publication date: 2008-06-11
Anticipated expiration: 2023-02-24
Also published as: JP2004255617A

Description

【０００１】
【発明の属する技術分野】
本発明は、光ディスクの基板等に使用されるディスクを成形するための金型、特に、ディスクの外周側面を形成する部材を、ディスクの上面を形成する部材と下面を形成する部材の間に挟んだ構造を有するディスク成形用金型に関する。
【０００２】
【従来の技術】
光ディスクの基板等に使用されるディスクを製造する方法として、通常、樹脂の射出成形が用いられている。ディスクの外周側面を形成するための部材（以下、外周側面形成部材と称する）を、ディスクの上面を形成する部材と下面を形成する部材の間に挟んだ構造は、例えば、スタンパをディスクの上面と下面の形成双方に適用する場合のディスク成形用金型として用いられている（例えば特許文献１参照）。
【０００３】
特許文献１に記載された金型では、外周部に図７〜９に示されるような断面構造が用いられる。図７に示す構造では、一方のスタンパ１０４を、外周リング１０３により隙間を持たせて鏡面盤１０１側に押さえ、他方のスタンパ１０５と外周リング１０３との間の隙間を、鏡面盤１０２に固定したクリアランス調整リング１０６で調整している。また、図８に示す構造では、上下に２分した外周リング１０３ａ、１０３ｂを用い、スタンパ１０４，１０５を各々外周リング１０３ａ、１０３ｂにより隙間を持たせて押さえ、さらに外周リング１０３ａ、１０３ｂ相互間にも、互いに対向した状態で隙間を設けている。図９に示す構造では、厚さ方向に隙間を設けた一体の外周リング１０３を一方の鏡面盤１０１に固定し、他方の鏡面盤１０２にクリアランス調整リング１０６を設けている。
【０００４】
また、上下の金型により形成されるキャビティに樹脂を充填する際に、充填に伴ってキャビティに発生するガスを排気する必要があり、そのための構造が例えば、特許文献２に記載されている。特許文献２のディスク成形用金型では、金型の複数の部材に連通した通路を設けることにより、吸引回路を形成している。
【０００５】
【特許文献１】
特開２０００−３３９７８１号公報
【０００６】
【特許文献２】
特開２００１−７９８８８号公報
【０００７】
【発明が解決しようとする課題】
外周側面形成部材をディスクの上面と下面を形成する部材の間に挟んだ構造の場合には、樹脂の充填の際に樹脂圧が型締圧より大きいと金型が開いて、例えば外周リングが固定していない側のスタンパと外周リングとの間の隙間が拡大し、そこに樹脂が侵入してバリが発生しやすくなるという問題がある。また、外周リングが２分割され、分割により形成された各部材がディスクの上面または下面を形成する部材に各々個別に固定されている場合は、外周リング同士が対向する部分に形成される隙間が拡大し、そこに樹脂が侵入してバリが発生し易くなるという問題がある。
【０００８】
また、特許文献２に記載された上述の吸引回路は、金型の複数の部材に連通した通路を設けるための加工が複雑であるため、実用上好適なものではなかった。
【０００９】
本発明はそのような問題を解消するために、ディスクの外周側面を形成する部材をディスクの上面と下面を形成する部材の間に挟んだ構造を有し、樹脂充填時に金型が少し開いた場合でもバリの発生を抑制できるディスク成形用金型、およびそのような金型を用いたディスク製造方法を提供することを目的とする。
【００１０】
また、キャビティに発生するガスを排気するための、簡素な構造の排気通路を有するディスク成形用金型を提供することを目的とする。
【００１１】
【課題を解決するための手段】
本発明のディスク成形用金型は、ディスクの上面を形成する上面形成部材と、前記ディスクの下面を形成する下面形成部材と、前記上面形成部材と前記下面形成部材の間に挟まれるように配置されて前記ディスクの外周側面を形成する外周側面形成部材とを備える。上記課題を解決するために、前記外周側面形成部材は、前記ディスクの厚さ方向に２分して形成された上部半体と下部半体とを含み、前記上部半体と下部半体の互いに対向する面に、キャビティの厚さ方向に平行な嵌合面を各々備え、前記上部半体及び下部半体の少なくとも一方における前記嵌合面より外側の面に、周方向に間欠的に配置された突起部が設けられ、金型を閉じた状態で、前記突起部が前記上部半体及び下部半体の他方と当接し、前記上部半体と下部半体の間の前記嵌合面より内側のディスクの厚さ方向の隙間が１０μｍ以上３０μｍ以下の範囲である。
【００１２】
本発明のディスク製造方法は、上記構成のディスク成形用金型を用い、キャビティ側における前記外周側面形成部材の前記上部半体と下部半体の間の隙間を、樹脂充填時に３０μｍ以下に制限することを特徴とする。
【００１３】
【発明の実施の形態】
本発明のディスク成形用金型によれば、金型が閉じた状態では、外周側面形成部材の上部半体と下部半体とは互いに突き当たり、キャビティの厚さを規定している。そして、上部半体と下部半体とは、キャビティの厚さ方向に形成された互いに平行な嵌合面を有する。そのため、金型が型締め状態から開いた場合でも、キャビティから金型の外へのガス逃げ状態は変化しないためバリの発生が抑制される。
【００１４】
前記突起部は、周方向に等間隔に配置されることが好ましい。また、前記上部半体および前記下部半体の嵌合面から前記ディスクの外周側面までのディスク径方向の距離が１ｍｍ以上３ｍｍ以下であることが好ましい。
【００１５】
また、本発明の他の構成のディスク成形用金型は、ディスクの上面を形成する上面形成部材と、前記ディスクの下面を形成する下面形成部材と、前記上面形成部材と前記下面形成部材の間に挟まれるように配置されて前記ディスクの外周側面を形成する外周側面形成部材とを備え、前記外周側面形成部材は、前記ディスクの厚さ方向に２分して形成された上部半体と下部半体とを含み、前記上部半体と下部半体の互いに対向する面に、ディスクの厚さ方向に平行な嵌合面を各々備え、前記外周側面形成部材より外側に、ディスクの厚さ方向において互いに突き当たる一対の突き当て部材を備え、前記外周側面形成部材の上部半体と下部半体を当接させた状態での厚みの合計よりも、前記一対の突き当て部材の厚みの合計の方が大きく、前記外周側面形成部材と前記上面形成部材または前記下面形成部材との間の隙間、または前記外周側面形成部材の前記上部半体と下部半体間の隙間が、キャビティ側の領域よりもキャビティから遠い側の領域において広く、キャビティ側の隙間の径方向における長さが１ｍｍ以上３ｍｍ以下であり、前記外周側面形成部材と前記上面形成部材または前記下面形成部材との間の最小隙間が１０μｍ以上３０μｍ以下である。
一対の前記突き当て部材は、互いに対向する面に各々テーパ部が設けられ、互いに突き当たるときに前記テーパ部が嵌合するように構成されることが好ましい。
【００１６】
前記外周側面形成部材より外側が一対の互いに突き当たる突き当て部材で覆われ、少なくとも一方の前記突き当て部材に吸引通路が設けられた構成とすることができる。その場合、一対の前記突き当て部材の間に互いに突き当たる面と突き当たらない面が設けられ、突き当たらない面にひと続きの弾性体が配置された構成としてもよい。また、前記突き当て部材に形成された溝に前記弾性体の一部が埋められた構成としてもよい。
【００１８】
前記上面形成部材または前記下面形成部材の少なくとも一方にスタンパが装着された構成とすることができる。また、前記上面形成部材または前記下面形成部材の少なくとも一方に低熱伝導板が装着された構成としてもよい。前記スタンパ裏面に低熱伝導板が敷かれた構成としてもよい。
【００１９】
以下に、本発明の実施の形態について、図面を参照して詳細に説明する。
【００２０】
（実施の形態１）
実施の形態１におけるディスク成形用金型の主要部を、図１に断面図で示す。この金型は、固定金型１と可動金型２とからなる。固定金型１は、中央部から順に、スプルブッシュ３、固定側固定ブッシュ４、固定側スタンパホルダー５、および固定側鏡面盤６が配置された構造を有する。スプルブッシュ３から溶融樹脂を流入させる。固定側スタンパホルダー５は、スタンパ７の内周部を固定側鏡面盤６に固定する機能を有する。スタンパ７の外周部の固定は、固定側外周リング８によって行う。
【００２１】
可動金型２は、中央部から順に、エジェクタピン９、カットパンチ１０、エジェクタスリーブ１１、可動側スタンパホルダー１２、可動側鏡面盤１３が配置された構造を有する。エジェクタピン９とエジェクタスリーブ１１は、成形されたディスクを金型内から取り出す際に突き出す機能を有する。カットパンチ１０は、成形ディスクに内孔を形成する機能を有する。可動側スタンパホルダー１２は、スタンパ１４の内周部を可動側鏡面盤１３に固定する機能を有する。スタンパ１４の外周部の固定は、可動側外周リング１５によって行う。
【００２２】
固定金型１と可動金型２とが閉じた図１の状態では、固定側外周リング８と可動側外周リング１５とは互いに突き当たり、キャビティ１６の厚さを規定している。固定側外周リング８と可動側外周リング１５とは、キャビティ１６の厚さ方向に形成された互いに平行な嵌合面８ａ、１５ａを有する。そのため、固定金型１と可動金型２とが型締め状態から開いた場合でも、キャビティ１６から金型の外へのガス逃げ状態は変化しないためバリの発生は抑制される。固定側外周リング８と可動側外周リング１５との間の隙間にバリが発生しないためには、金型が開く量は３０μｍ以下に制限されることが望ましい。
【００２３】
図２（ａ）は、可動側外周リング１５を可動側から見た平面図である。図２（ａ）におけるＡＢ断面を矢印の向きに見た図を図２（ｂ）に示す。図２（ａ）に示すように、可動側外周リング１５には、径方向に延びた溝１５ｂが、周方向に４５度おきに８箇所設けられている。そのため、キャビティ１６に発生したガスは、まず可動側外周リング１５とスタンパ１４との間の隙間を通じて外方に逃げ、次に可動側外周リング１５に設けられた溝１５ｂを通じてさらに金型の外側に逃げる。同様に固定金型１についても、固定側外周リング８とスタンパ７との間に隙間が形成され、固定側外周リング８にも可動側外周リング１５と同様にガス逃げ用の溝が設けられる。固定側外周リング８とスタンパ７との間の隙間および可動側外周リング１５とスタンパ１４との間の隙間は、ガス逃げとバリ抑制の両立の観点から１０μｍ以上３０μｍ以下が望ましかった。
【００２４】
図１に示した構造では、固定側外周リング８と可動側外周リング１５とは、ディスクに平行な面が全面において互いに当接するが、嵌合面８ａ、１５ａを挟んでキャビティ１６側の面だけ、あるいはキャビティ１６から遠い側の面だけが当接するように構成することも可能である。この場合は２つの異なる面で当接させる必要がなくなるため、部材の加工が容易になるという効果が得られる。固定側外周リング８と可動側外周リング１５との間の隙間は、樹脂充填時に金型が開いても、キャビティ１６側において３０μｍ以下であることが、バリを発生させないために望ましい。
【００２５】
（実施の形態２）
実施の形態２におけるディスク成形用金型について、図３を参照して説明する。この金型は、実施の形態１のディスク成形用金型とは、固定側外周リング８と可動側外周リング１５の形状が異なる。実施の形態１では固定側外周リング８と可動側外周リング１５とが周方向については全面で突き当たるのに対して、実施の形態２では、固定側外周リングと可動側外周リングとの間に内側から外側に通じる隙間を設ける。図３（ａ）に、本実施の形態の可動側外周リング１７を固定側金型１（図１参照）側から見た平面図を示す。図３（ｂ）にＣＤ断面を、図３（ｃ）にＣＥ断面をそれぞれ示す。
【００２６】
ＣＤ断面は、可動側外周リング１７における突起部１７ｂが形成された箇所に相当し、ＣＥ断面は、可動側外周リング１７における突起部以外の平坦部１７ａに相当する。突起部１７ｂを周方向に４５°間隔で設ける。本実施の形態における固定側外周リング（図示せず）は、突起部のない実施の形態１の場合の固定側外周リング８と同様の構造でよいので、以下の説明では固定側外周リング８として説明する。可動側外周リング１７の突起部１７ｂを固定側外周リング８に当接させることで、固定側外周リング８と可動側外周リング１７との間の隙間を規定する。
【００２７】
この場合でも、実施の形態１と同様、固定側外周リング８と可動側外周リング１７とには、キャビティ１６の厚さ方向に形成された互いに平行な嵌合面８ａ、１７ｃを有する。それにより、固定金型１と可動金型２とが型締め状態から開いてもキャビティ１６から金型の外へのガス逃げ状態は変化せず、その結果、バリの発生は抑制される。固定側外周リング８と可動側外周リング１７との間の隙間にバリが発生しないためには、樹脂充填時でのこの隙間が、キャビティ１６側において３０μｍ以下であることが望ましい。また、ガス逃げのためにはこの隙間は１０μｍ以上必要である。
【００２８】
本実施の形態の構造によれば、実施の形態１と比べてガス逃げの通路が増すため、ガス逃げがより良化される効果が得られる。ガス逃げを周方向に均等にさせるため、固定側外周リング８と可動側外周リング１７との突き当て部は、キャビティ１６近傍に設けないことが好ましい。また、突き当て部は周方向に均等に設けることが望ましい。
【００２９】
また、キャビティ１６から、固定側外周リング８と可動側外周リング１５に設けた嵌合面８ａ、１７ｃまでの距離は、加工性とガス逃げの観点から１ｍｍ以上３ｍｍ以下が望ましい。
【００３０】
上述の構成では、固定側外周リング８と可動側外周リング１７の突き当て部における突起部１７ｂを可動側外周リング１７に設けた例を示したが、固定側外周リング８に設けること、あるいは固定側外周リング８と可動側外周リング１７の両方に設けることも可能である。
【００３１】
（実施の形態３）
実施の形態３におけるディスク成形用金型の外周部近傍を、図４に断面図で示す。この金型は、固定側外周リング１８と可動側外周リング１９の形状、およびそれより外周の形状が、実施の形態２のディスク成形用金型と異なる。
【００３２】
図４に示すように固定金型１では、固定側外周リング１８の外側に固定側突き当てリング２０が配置され、この固定側突き当てリング２０は固定側鏡面盤６に固定されている。また、可動金型２では、可動側外周リング１９の外側に可動側突き当てリング２１が配置され、この可動側突き当てリング２１は可動側鏡面盤１３に固定されている。固定側突き当てリング２０と可動側突き当てリング２１とは、固定金型１と可動金型２とが閉じた場合に互いに突き当たり、キャビティ１６の厚さを規定している。
【００３３】
この結果、固定金型１と可動金型２とが閉じた状態でも、固定側外周リング１８と可動側外周リング１９との間には隙間ができる。この隙間は、ガス逃げのためには１０μｍ以上であることが望ましく、この隙間によってキャビティ１６内からのガス逃げが助長される。また、樹脂の充填時に金型が開いた場合でもバリを抑制するために、この隙間は３０μｍ以下が望ましい。
【００３４】
固定側外周リング１８とスタンパ７との間の隙間、および可動側外周リング１９とスタンパ１４との間の隙間は、キャビティ１６に隣接る側で狭く外方に離れると広くなっている。この構造により流動抵抗が減少するため、ガス逃げがよくなる効果が得られる。この隙間における最小隙間は、バリが発生しないためには３０μｍ以下が望ましく、ガス逃げのためには１０μｍ以上が望ましかった。また、これらの最小隙間となる領域の径方向の長さは、加工性とガス逃げのし易さから１ｍｍ以上３ｍｍ以下が良好であった。
【００３５】
実施の形態３では、固定側突き当てリング２０と可動側突き当てリング２１とがテーパをもって嵌合する構造になっている。この構造により、固定側突き当てリング２０と可動側突き当てリング２１とが嵌合することで芯出しができる効果が得られる。但し、固定側突き当てリング２０と可動側突き当てリング２１とが互いに突き当たるだけの構造でも、本実施の形態の効果は得られる。
【００３６】
実施の形態３に基づく具体的な実施例では、固定側外周リング１８と可動側外周リング１９との間の隙間は、キャビティ１６からキャビティ１６の厚さ方向に平行な嵌合面までは一定としたが、キャビティ１６から遠い領域で広げても良い。この場合の最小隙間を有する領域の幅は、加工性とガス逃げのし易さから１ｍｍ以上３ｍｍ以下が良好であった。
【００３７】
（実施の形態４）
実施の形態４におけるディスク成形用金型の外周部近傍を、図５に断面図で示す。この金型は実施の形態３の金型に対して、固定側突き当てリング２２の外周側面に吸引通路２４を設けている点が異なる。吸引通路２４の先には真空発生装置、例えば、真空ポンプやコンバムが接続される（図示せず）。
【００３８】
従来例における吸引回路は、上述のように、金型の複数の部材に亙って続いた通路を設ける必要があり加工が複雑であった。これに対して本実施の形態では、図５に示したように、固定側突き当てリング２２と可動側突き当てリング２３の内側にある固定側外周リング１８と可動側外周リング１９に、内側から外側に通じる溝や孔が設けられている。したがって、固定金型１と可動金型２とを閉じて、固定側突き当てリング２２と可動側突き当てリング２３とにより固定側外周リング１８と可動側外周リング１９の外側が封鎖されると、固定側突き当てリング２２に設けられた吸引通路２４から吸引することで、キャビティ１６から強制的にガス逃げが行われ、ガス逃げのための構成が簡単になる。
【００３９】
上述の構成では、実施の形態３のディスク成形用金型の外周リングの構造に対して、固定側突き当てリング２２に吸引通路２４を設ける場合を示したが、可動側突き当てリング２３に吸引通路２４を設けても良い。
【００４０】
（実施の形態５）
実施の形態５におけるディスク成形用金型の外周部近傍を、図６に断面図で示す。この金型は実施の形態４に対して、固定側突き当てリング２５と可動側突き当てリング２６とが一面で突き当たり、他面はバイトン等の耐熱性ゴムからなる弾性体２７を介して接触する点が異なる。弾性体２７は固定側突き当てリング２５に接着されており、ひと続きの環状である。この構造では弾性体２７を設けることで、固定金型１と可動金型２とが樹脂の充填時に少し開いたとしても、固定側突き当てリング２５と可動側突き当てリング２６とが弾性体２７を介して接触した状態を保持できる。そのため、吸引通路２４を介して行われる金型内の真空吸引の状態が保持され、キャビティ１６からのガス逃げの働きを維持することができる。
【００４１】
この弾性体２７は、可動側突き当てリング２６に設けることも可能である。また、この弾性体２７は、固定側突き当てリング２５と可動側突き当てリング２６の内側の面上に配置しても、外側の面上に配置してもよい。いずれかの面に溝を形成して、弾性体２７をその溝の中に装着してもよい。
【００４２】
以上の実施の形態では、スタンパの外周を外周リングで機械的に固定する場合のみを示したが、鏡面盤に溝を設け真空吸引通路と繋ぐことで、スタンパの外周を真空吸引して固定する構造とすることも可能である。
【００４３】
また以上の実施の形態では、固定金型と可動金型の両方にスタンパが設置される場合を示したが、ディスク状のものを成形する場合であれば、スタンパが一方のみに設置される場合でも、あるいはスタンパが全く設置されない場合でも、本発明を適用することができる。
【００４４】
また以上の実施の形態では鏡面盤にスタンパを装着する場合を示したが、スタンパ以外に低熱伝導板のような環状板を設けても良いし、スタンパ裏面に低熱伝導板を敷いた場合であっても、本発明を適用することができる。
【００４５】
【発明の効果】
本発明によれば、ディスクの外周側面を形成する部材をディスクの上面と下面を形成する部材の間に挟んだ構造を有するディスク成形用金型において、樹脂充填時に金型が少し開いた場合でもバリの発生を抑制できる構造を実現できる。
【図面の簡単な説明】
【図１】本発明の実施の形態１におけるディスク成形用金型の主要部の構成を示す概略断面図
【図２】図１のディスク成形用金型を構成する可動側外周リングを示し、（ａ）は平面図、（ｂ）は（ａ）のＡＢ断面の矢視図
【図３】実施の形態２におけるディスク成形用金型の可動側外周リングを示し、（ａ）は平面図、（ｂ）は（ａ）のＣＤ断面図、（ｃ）は（ａ）のＣＥ断面図
【図４】実施の形態３におけるディスク成形用金型の外周部の構成を示す部分断面図
【図５】実施の形態４におけるディスク成形用金型の外周部の構成を示す部分断面図
【図６】実施の形態５におけるディスク成形用金型の外周部の構成を示す部分断面図
【図７】従来例のディスク成形用金型の外周部の構成を示す部分断面図
【図８】従来例のディスク成形用金型の外周部の他の構成を示す部分断面図
【図９】従来例のディスク成形用金型の外周部の更に他の構成を示す部分断面図
【符号の説明】
１固定金型
２可動金型
３スプルブッシュ
４固定側固定ブッシュ
５固定側スタンパホルダー
６固定側鏡面盤
７、１４スタンパ
８、１８固定側外周リング
８ａ、１５ａ、１７ｃ嵌合面
９エジェクタピン
１０カットパンチ
１１エジェクタスリーブ
１２可動側スタンパホルダー
１３可動側鏡面盤
１５、１７、１９可動側外周リング
１５ｂ溝
１６キャビティ
１７ａ平坦部
１７ｂ突起部
２０、２２、２５固定側突き当てリング
２１、２３、２６可動側突き当てリング
２４吸引通路
２７弾性体
１０１、１０２鏡面盤
１０３、１０３ａ、１０３ｂ外周リング
１０４、１０５スタンパ
１０６クリアランス調整リング[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold for molding a disk used for an optical disk substrate or the like, in particular, a member that forms the outer peripheral side surface of the disk is sandwiched between a member that forms the upper surface of the disk and a member that forms the lower surface. The present invention relates to a mold for forming a disc having an elliptical structure.
[0002]
[Prior art]
As a method of manufacturing a disk used for an optical disk substrate or the like, resin injection molding is usually used. A structure in which a member for forming the outer peripheral side surface of the disk (hereinafter referred to as an outer peripheral side surface forming member) is sandwiched between a member that forms the upper surface of the disk and a member that forms the lower surface is, for example, a stamper. It is used as a disk molding die when applied to both the formation of the lower surface and the lower surface (see, for example, Patent Document 1).
[0003]
In the mold described in Patent Document 1, a cross-sectional structure as shown in FIGS. In the structure shown in FIG. 7, one stamper 104 is pressed to the mirror surface plate 101 side with a gap by the outer ring 103, and the gap between the other stamper 105 and the outer ring 103 is fixed to the mirror plate 102. The clearance adjustment ring 106 is used for adjustment. Further, in the structure shown in FIG. 8, the outer peripheral rings 103a and 103b which are divided into upper and lower parts are used, the stampers 104 and 105 are pressed by the outer peripheral rings 103a and 103b, respectively, and are further held between the outer peripheral rings 103a and 103b. Also, a gap is provided in a state of facing each other. In the structure shown in FIG. 9, an integral outer ring 103 having a gap in the thickness direction is fixed to one mirror surface plate 101, and a clearance adjustment ring 106 is provided on the other mirror surface plate 102.
[0004]
Moreover, when filling the cavity formed by the upper and lower molds with the resin, it is necessary to exhaust the gas generated in the cavity along with the filling, and a structure for that purpose is described in Patent Document 2, for example. In the disk molding die of Patent Document 2, a suction circuit is formed by providing a passage communicating with a plurality of members of the die.
[0005]
[Patent Document 1]
JP-A-2000-339781 [0006]
[Patent Document 2]
Japanese Patent Laid-Open No. 2001-79888
[Problems to be solved by the invention]
In the case of a structure in which the outer peripheral side surface forming member is sandwiched between the members forming the upper surface and the lower surface of the disk, the mold opens when the resin pressure is larger than the mold clamping pressure during resin filling, for example, the outer ring There is a problem that the gap between the stamper on the non-fixed side and the outer ring is enlarged, and the resin easily enters there to easily generate burrs. In addition, when the outer ring is divided into two and each member formed by the division is individually fixed to the member forming the upper surface or the lower surface of the disk, there is a gap formed in the portion where the outer rings are opposed to each other. There is a problem that the resin is enlarged and burrs are easily generated when the resin enters.
[0008]
Further, the above-described suction circuit described in Patent Document 2 is not practically suitable because the processing for providing a passage communicating with a plurality of members of the mold is complicated.
[0009]
In order to solve such a problem, the present invention has a structure in which a member that forms the outer peripheral side surface of the disc is sandwiched between members that form the upper surface and the lower surface of the disc, and the mold is slightly opened during resin filling. It is an object of the present invention to provide a disk molding die that can suppress the occurrence of burrs, and a disk manufacturing method using such a mold.
[0010]
It is another object of the present invention to provide a disk molding die having an exhaust passage having a simple structure for exhausting gas generated in a cavity.
[0011]
[Means for Solving the Problems]
The disc molding die of the present invention is disposed so as to be sandwiched between an upper surface forming member that forms the upper surface of the disc, a lower surface forming member that forms the lower surface of the disc, and the upper surface forming member and the lower surface forming member. And an outer peripheral side surface forming member that forms an outer peripheral side surface of the disk. In order to solve the above problems, the outer peripheral side surface forming member includes an upper half and a lower half formed by dividing the disk in the thickness direction, and the upper half and the lower half are connected to each other. The opposing surfaces are each provided with a mating surface parallel to the thickness direction of the cavity, and are intermittently arranged in the circumferential direction on the outer surface of the mating surface in at least one of the upper half and the lower half. In the state where the protrusion is provided and the mold is closed, the protrusion abuts the other of the upper half and the lower half, and is inside the fitting surface between the upper half and the lower half. The gap in the thickness direction of the disc is in the range of 10 μm to 30 μm .
[0012]
The disk manufacturing method of the present invention uses the disk molding die having the above-described configuration, and restricts the gap between the upper half and the lower half of the outer peripheral side surface forming member on the cavity side to 30 μm or less during resin filling. It is characterized by that.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
According to the disc molding die of the present invention, when the die is closed, the upper half and the lower half of the outer peripheral side surface forming member abut each other to define the thickness of the cavity. The upper half and the lower half have mating surfaces parallel to each other formed in the thickness direction of the cavity. Therefore, even when the mold is opened from the clamped state, the gas escape state from the cavity to the outside of the mold does not change, so that the generation of burrs is suppressed.
[0014]
Before SL protrusions have preferably be arranged at equal intervals in the circumferential direction. Moreover, it is preferable that the distance of the disk radial direction from the fitting surface of the said upper half body and the said lower half body to the outer peripheral side surface of the said disk is 1 mm or more and 3 mm or less.
[0015]
Also, other disk molding mold structure of the present invention includes a top surface forming member for forming the upper surface of the disk, and a lower surface forming member for forming a lower surface of the disk, of the lower surface forming member and the upper surface forming member An outer peripheral side surface forming member that is disposed so as to be sandwiched between and forms an outer peripheral side surface of the disk, and the outer peripheral side surface forming member is divided into two in the thickness direction of the disk; Each of the upper half and the lower half are opposed to each other on the surfaces facing each other in parallel with the thickness direction of the disk. A pair of abutting members that abut against each other in the direction, and the total thickness of the pair of abutting members is greater than the total thickness in a state where the upper half and the lower half of the outer peripheral side surface forming member are in contact with each other. it is rather large, the outer The gap between the side surface forming member and the upper surface forming member or the lower surface forming member, or the gap between the upper half and the lower half of the outer peripheral side surface forming member is located on the side farther from the cavity than the cavity side region. Wide in the region, the length of the gap on the cavity side in the radial direction is 1 mm or more and 3 mm or less, and the minimum gap between the outer peripheral side surface forming member and the upper surface forming member or the lower surface forming member is 10 μm or more and 30 μm or less. .
The pair of abutting members are preferably configured such that tapered portions are provided on surfaces facing each other, and the tapered portions are fitted when they abut against each other.
[0016]
An outer side of the outer peripheral side surface forming member may be covered with a pair of abutting members that abut each other, and a suction passage may be provided in at least one of the abutting members. In that case, it is good also as a structure by which the surface which does not collide and the surface which does not collide mutually is provided between a pair of said abutting members, and a continuous elastic body is arrange | positioned on the surface which does not collide. Moreover, it is good also as a structure by which a part of said elastic body was buried in the groove | channel formed in the said abutting member.
[0018]
A stamper may be mounted on at least one of the upper surface forming member and the lower surface forming member. Moreover, it is good also as a structure by which the low heat conductive board was mounted | worn with at least one of the said upper surface formation member or the said lower surface formation member. A low thermal conductive plate may be laid on the stamper back surface.
[0019]
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0020]
(Embodiment 1)
The main part of the disk molding die in the first embodiment is shown in a sectional view in FIG. This mold includes a fixed mold 1 and a movable mold 2. The fixed mold 1 has a structure in which a sprue bush 3, a fixed-side fixed bush 4, a fixed-side stamper holder 5, and a fixed-side specular panel 6 are arranged in this order from the center. Molten resin is caused to flow from the sprue bush 3. The fixed-side stamper holder 5 has a function of fixing the inner peripheral portion of the stamper 7 to the fixed-side mirror surface plate 6. The outer peripheral portion of the stamper 7 is fixed by a fixed outer peripheral ring 8.
[0021]
The movable mold 2 has a structure in which an ejector pin 9, a cut punch 10, an ejector sleeve 11, a movable side stamper holder 12, and a movable side specular disc 13 are arranged in this order from the center. The ejector pin 9 and the ejector sleeve 11 have a function of projecting when the molded disk is taken out from the mold. The cut punch 10 has a function of forming an inner hole in the molding disk. The movable side stamper holder 12 has a function of fixing the inner peripheral portion of the stamper 14 to the movable side mirror surface plate 13. The outer peripheral portion of the stamper 14 is fixed by a movable outer peripheral ring 15.
[0022]
In the state of FIG. 1 in which the fixed mold 1 and the movable mold 2 are closed, the fixed outer peripheral ring 8 and the movable outer peripheral ring 15 abut each other and define the thickness of the cavity 16. The fixed outer peripheral ring 8 and the movable outer peripheral ring 15 have fitting surfaces 8 a and 15 a that are formed in the thickness direction of the cavity 16 and are parallel to each other. Therefore, even when the fixed mold 1 and the movable mold 2 are opened from the mold-clamping state, the gas escape state from the cavity 16 to the outside of the mold does not change, so that the generation of burrs is suppressed. In order to prevent burrs from being generated in the gap between the fixed outer ring 8 and the movable outer ring 15, it is desirable that the amount of opening of the mold is limited to 30 μm or less.
[0023]
FIG. 2A is a plan view of the movable outer peripheral ring 15 as viewed from the movable side. FIG. 2B shows a view of the AB cross section in FIG. As shown in FIG. 2A, the movable-side outer peripheral ring 15 is provided with eight grooves 15b extending in the radial direction every 45 degrees in the circumferential direction. Therefore, the gas generated in the cavity 16 first escapes outward through the gap between the movable outer ring 15 and the stamper 14, and then further to the outside of the mold through the groove 15b provided in the movable outer ring 15. escape. Similarly, in the fixed mold 1, a gap is formed between the fixed outer peripheral ring 8 and the stamper 7, and a gas escape groove is also provided in the fixed outer peripheral ring 8 in the same manner as the movable outer peripheral ring 15. The gap between the fixed outer ring 8 and the stamper 7 and the gap between the movable outer ring 15 and the stamper 14 are preferably 10 μm or more and 30 μm or less from the viewpoint of achieving both gas escape and burr suppression.
[0024]
In the structure shown in FIG. 1, the fixed outer peripheral ring 8 and the movable outer peripheral ring 15 are in contact with each other on the entire surface parallel to the disk, but only the surface on the cavity 16 side with the fitting surfaces 8a and 15a interposed therebetween. Alternatively, only the surface far from the cavity 16 may be in contact. In this case, since it is not necessary to make contact on two different surfaces, an effect that the processing of the member becomes easy can be obtained. The gap between the fixed outer ring 8 and the movable outer ring 15 is preferably 30 μm or less on the cavity 16 side even if the mold is opened during resin filling, so that no burrs are generated.
[0025]
(Embodiment 2)
A disk molding die in the second embodiment will be described with reference to FIG. This mold is different from the disk molding mold of the first embodiment in the shapes of the fixed-side outer ring 8 and the movable-side outer ring 15. In the first embodiment, the fixed-side outer ring 8 and the movable-side outer ring 15 abut against the entire surface in the circumferential direction, whereas in the second embodiment, the inner side between the fixed-side outer ring and the movable-side outer ring. Provide a gap that leads to the outside. FIG. 3A shows a plan view of the movable-side outer peripheral ring 17 of the present embodiment as viewed from the fixed-side mold 1 (see FIG. 1). FIG. 3B shows a CD cross section, and FIG. 3C shows a CE cross section.
[0026]
The CD cross section corresponds to a portion where the protrusion 17 b is formed in the movable outer peripheral ring 17, and the CE cross section corresponds to a flat portion 17 a other than the protrusion in the movable outer peripheral ring 17. The protrusions 17b are provided at 45 ° intervals in the circumferential direction. The fixed-side outer ring (not shown) in the present embodiment may have the same structure as that of the fixed-side outer ring 8 in the first embodiment having no protrusions, and therefore, in the following description, as the fixed-side outer ring 8 explain. By causing the protrusion 17 b of the movable outer ring 17 to contact the fixed outer ring 8, a gap between the fixed outer ring 8 and the movable outer ring 17 is defined.
[0027]
Even in this case, similarly to the first embodiment, the fixed outer peripheral ring 8 and the movable outer peripheral ring 17 have fitting surfaces 8 a and 17 c formed in the thickness direction of the cavity 16 and parallel to each other. Thereby, even if the fixed mold 1 and the movable mold 2 are opened from the mold clamping state, the gas escape state from the cavity 16 to the outside of the mold does not change, and as a result, the generation of burrs is suppressed. In order not to generate burrs in the gap between the fixed outer ring 8 and the movable outer ring 17, it is desirable that this gap when filled with resin is 30 μm or less on the cavity 16 side. Further, this gap needs to be 10 μm or more for gas escape.
[0028]
According to the structure of the present embodiment, the gas escape passage is increased as compared with the first embodiment, so that the effect of improving the gas escape can be obtained. In order to make the gas escape uniform in the circumferential direction, it is preferable that the abutting portion between the fixed outer peripheral ring 8 and the movable outer peripheral ring 17 is not provided in the vicinity of the cavity 16. Further, it is desirable that the abutting portions are provided evenly in the circumferential direction.
[0029]
In addition, the distance from the cavity 16 to the fitting surfaces 8a and 17c provided on the stationary outer ring 8 and the movable outer ring 15 is preferably 1 mm or more and 3 mm or less from the viewpoint of workability and gas escape.
[0030]
In the above-described configuration, the example in which the protruding portion 17b at the abutting portion between the fixed-side outer ring 8 and the movable-side outer ring 17 is provided on the movable-side outer ring 17 is provided. It is also possible to provide both the outer peripheral ring 8 and the movable outer peripheral ring 17.
[0031]
(Embodiment 3)
FIG. 4 is a cross-sectional view showing the vicinity of the outer peripheral portion of the disk molding die in the third embodiment. This mold is different from the disk molding mold of the second embodiment in the shapes of the fixed outer peripheral ring 18 and the movable outer peripheral ring 19 and the outer peripheral shape thereof.
[0032]
As shown in FIG. 4, in the fixed mold 1, a fixed-side abutment ring 20 is disposed outside the fixed-side outer peripheral ring 18, and the fixed-side abutment ring 20 is fixed to the fixed-side mirror surface plate 6. In the movable mold 2, a movable abutting ring 21 is disposed outside the movable outer peripheral ring 19, and the movable abutting ring 21 is fixed to the movable mirror surface plate 13. The fixed side abutting ring 20 and the movable side abutting ring 21 abut against each other when the fixed mold 1 and the movable mold 2 are closed, and define the thickness of the cavity 16.
[0033]
As a result, even when the fixed mold 1 and the movable mold 2 are closed, a gap is formed between the fixed outer peripheral ring 18 and the movable outer peripheral ring 19. This gap is desirably 10 μm or more for gas escape, and this gap promotes gas escape from the cavity 16. Further, this gap is preferably 30 μm or less in order to suppress burrs even when the mold is opened during resin filling.
[0034]
The gap between the fixed outer ring 18 and the stamper 7 and the gap between the movable outer ring 19 and the stamper 14 are narrower and wider on the side adjacent to the cavity 16. Since the flow resistance is reduced by this structure, an effect of improving gas escape can be obtained. The minimum gap in this gap is desirably 30 μm or less so as not to generate burrs, and 10 μm or more is desirable for gas escape. Moreover, the length in the radial direction of the region serving as the minimum gap was preferably 1 mm or more and 3 mm or less from the viewpoint of workability and ease of gas escape.
[0035]
In the third embodiment, the fixed side abutting ring 20 and the movable side abutting ring 21 are fitted with a taper. With this structure, the fixed side abutting ring 20 and the movable side abutting ring 21 are fitted to each other, so that an effect of centering can be obtained. However, the effect of the present embodiment can be obtained even with a structure in which the fixed-side butting ring 20 and the movable-side butting ring 21 just abut against each other.
[0036]
In a specific example based on the third embodiment, the gap between the fixed outer peripheral ring 18 and the movable outer peripheral ring 19 is constant from the cavity 16 to the fitting surface parallel to the thickness direction of the cavity 16. However, it may be spread in a region far from the cavity 16. In this case, the width of the region having the minimum gap was preferably 1 mm or more and 3 mm or less from the viewpoint of workability and ease of gas escape.
[0037]
(Embodiment 4)
FIG. 5 is a cross-sectional view showing the vicinity of the outer peripheral portion of the disk molding die in the fourth embodiment. This mold is different from the mold of the third embodiment in that a suction passage 24 is provided on the outer peripheral side surface of the fixed abutting ring 22. A vacuum generator, for example, a vacuum pump or a comb is connected to the tip of the suction passage 24 (not shown).
[0038]
As described above, the suction circuit in the conventional example is complicated in processing because it is necessary to provide a continuous passage through a plurality of members of the mold. On the other hand, in the present embodiment, as shown in FIG. 5, the fixed side outer ring 18 and the movable side outer ring 19 inside the fixed side abutting ring 22 and the movable side abutting ring 23 are connected to the inner side from the inner side. Grooves and holes leading to the outside are provided. Therefore, when the fixed mold 1 and the movable mold 2 are closed and the outside of the fixed outer ring 18 and the movable outer ring 19 is sealed by the fixed abutting ring 22 and the movable abutting ring 23, By suctioning from the suction passage 24 provided in the fixed side abutting ring 22, gas escape is forcibly performed from the cavity 16, and the configuration for gas escape becomes simple.
[0039]
In the configuration described above, the case where the suction passage 24 is provided in the fixed abutting ring 22 is shown in the structure of the outer peripheral ring of the disk molding die of the third embodiment. A passage 24 may be provided.
[0040]
(Embodiment 5)
FIG. 6 is a sectional view showing the vicinity of the outer peripheral portion of the disk molding die in the fifth embodiment. In this mold, the fixed-side butting ring 25 and the movable-side butting ring 26 are abutted on one surface and the other surface is in contact with the elastic body 27 made of heat-resistant rubber such as Viton. The point is different. The elastic body 27 is bonded to the fixed side abutting ring 25 and has a continuous ring shape. In this structure, by providing the elastic body 27, even if the fixed mold 1 and the movable mold 2 are slightly opened when the resin is filled, the fixed-side butting ring 25 and the movable-side butting ring 26 are elastic bodies 27. It is possible to maintain the contact state via the. Therefore, the state of vacuum suction in the mold performed through the suction passage 24 is maintained, and the function of gas escape from the cavity 16 can be maintained.
[0041]
The elastic body 27 can also be provided on the movable side abutting ring 26. The elastic body 27 may be disposed on the inner surface of the fixed abutting ring 25 and the movable abutting ring 26 or may be disposed on the outer surface. A groove may be formed on either surface, and the elastic body 27 may be mounted in the groove.
[0042]
In the above embodiment, only the case where the outer periphery of the stamper is mechanically fixed by the outer peripheral ring is shown. However, the outer periphery of the stamper is fixed by vacuum suction by providing a groove on the mirror plate and connecting it to the vacuum suction passage. A structure is also possible.
[0043]
Further, in the above embodiment, the case where the stamper is installed in both the fixed mold and the movable mold is shown. However, in the case of molding a disk-shaped one, the stamper is installed only in one side. However, the present invention can be applied even when no stamper is installed.
[0044]
In the above embodiments, the stamper is mounted on the mirror plate. However, an annular plate such as a low heat conductive plate may be provided in addition to the stamper, or the low heat conductive plate is laid on the back of the stamper. However, the present invention can be applied.
[0045]
【The invention's effect】
According to the present invention, in a disk molding die having a structure in which a member forming the outer peripheral side surface of the disk is sandwiched between members forming the upper surface and the lower surface of the disk, even when the mold is slightly opened during resin filling A structure capable of suppressing the generation of burrs can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing the configuration of a main part of a disk molding die in Embodiment 1 of the present invention. FIG. 2 shows a movable-side outer peripheral ring constituting the disk molding die of FIG. (a) is a plan view, (b) is an arrow view of the AB cross section of (a). FIG. 3 shows a movable side outer peripheral ring of a disk molding die in Embodiment 2, (a) is a plan view, (b) is a CD cross-sectional view of (a), (c) is a CE cross-sectional view of (a). [FIG. 4] FIG. 5 is a partial cross-sectional view showing the configuration of the outer periphery of a disk-molding mold in Embodiment 3. FIG. 6 is a partial cross-sectional view showing the configuration of the outer peripheral portion of the disk-forming mold in the fourth embodiment. FIG. 6 is a partial cross-sectional view showing the configuration of the outer peripheral portion of the disk-forming mold in the fifth embodiment. FIG. 8 is a partial cross-sectional view showing the configuration of the outer periphery of a disk molding die of FIG. Partial cross-sectional view showing another configuration of the outer peripheral portion of the mold Figure 9 further partial sectional view showing another configuration of the outer peripheral portion of the disk molding mold of the prior art [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Movable mold 3 Sprue bush 4 Fixed side fixed bush 5 Fixed side stamper holder 6 Fixed side mirror surface board 7, 14 Stamper 8, 18 Fixed side outer ring 8a, 15a, 17c Fitting surface 9 Ejector pin 10 Cut Punch 11 Ejector sleeve 12 Movable side stamper holder 13 Movable side mirror plate 15, 17, 19 Movable side outer ring 15 b Groove 16 Cavity 17 a Flat part 17 b Protrusion part 20, 22, 25 Fixed side abutment ring 21, 23, 26 Movable side Abutting ring 24 Suction passage 27 Elastic body 101, 102 Mirror plate 103, 103a, 103b Outer ring 104, 105 Stamper 106 Clearance adjustment ring

Claims

An upper surface forming member for forming the upper surface of the disk, a lower surface forming member for forming the lower surface of the disk, and an outer peripheral side surface of the disk are disposed so as to be sandwiched between the upper surface forming member and the lower surface forming member. In a disk molding die provided with an outer peripheral side surface forming member,
The peripheral side surface forming member, wherein the includes a thickness direction is formed by 2 minutes the upper half of the disc and the lower half, the opposing surfaces of the upper half and the lower half, the thickness of the disc Each has a parallel mating surface ,
Protrusions intermittently arranged in the circumferential direction are provided on the outer surface of the fitting surface in at least one of the upper half and the lower half,
In a state where the mold is closed, the protrusion comes into contact with the other of the upper half and the lower half, and is in the thickness direction of the disk inside the fitting surface between the upper half and the lower half. A disc molding die, wherein the gap is in the range of 10 μm to 30 μm .

Claim 1 disk molding mold according to the projections are arranged at equal intervals in the circumferential direction.

The disk molding die according to claim 1 or 2, wherein a distance in a disk radial direction from a fitting surface of the upper half and the lower half to an outer peripheral side surface of the disk is 1 mm or more and 3 mm or less.

An upper surface forming member for forming the upper surface of the disk, a lower surface forming member for forming the lower surface of the disk, and an outer peripheral side surface of the disk are disposed so as to be sandwiched between the upper surface forming member and the lower surface forming member. In a disk molding die provided with an outer peripheral side surface forming member,
The outer peripheral side surface forming member includes an upper half and a lower half formed by dividing the disk in the thickness direction of the disk, and the thickness of the disk is formed on the surfaces of the upper half and the lower half facing each other. Each has a parallel mating surface,
Provided with a pair of abutting members that abut each other in the disc thickness direction on the outer peripheral side of the outer peripheral side surface forming member, and the total thickness in a state where the upper half and the lower half of the outer peripheral side surface forming member are in contact with each other than even towards the total thickness of the pair of abutting members rather large,
A gap between the outer peripheral side surface forming member and the upper surface forming member or the lower surface forming member, or a gap between the upper half body and the lower half body of the outer peripheral side surface forming member is farther from the cavity than the cavity side region. Wide in the side area,
The length in the radial direction of the gap on the cavity side is 1 mm or more and 3 mm or less,
Disk mold, wherein the minimum gap between the upper surface forming member or the lower surface forming member and the outer peripheral side surface forming member is 10μm or more 30μm or less.

5. The disk molding die according to claim 4 , wherein each of the pair of abutting members is provided with a tapered surface on a surface facing each other, and the tapered portion is fitted when abutting each other.

6. The disk molding die according to claim 4, wherein an outer side of the outer peripheral side surface forming member is covered with a pair of abutting members that abut each other, and a suction path is provided in at least one of the facing members.

The disk molding gold according to any one of claims 4 to 6 , wherein a surface that faces each other and a surface that does not contact each other are provided between the pair of abutting members, and a continuous elastic body is disposed on the surface that does not contact each other. Type.

The disk molding die according to any one of claims 4 to 7 , wherein a part of the elastic body is buried in a groove formed in the abutting member.

The disk molding die according to any one of claims 1 to 8, wherein a stamper is mounted on at least one of the upper surface forming member and the lower surface forming member.

The disk molding die according to any one of claims 1 to 9, wherein a low thermal conductive plate is mounted on at least one of the upper surface forming member and the lower surface forming member.

The disk molding die according to any one of claims 1 to 10, wherein a low thermal conductive plate is laid on the rear surface of the stamper.

A disk manufacturing method using the disk molding die according to claim 1, wherein a gap between the outer peripheral side surface forming member and the lower half on the cavity side is limited to 30 μm or less during resin filling.

Using the disk molding die according to claim 6 , the inside of the cavity is vacuum-sucked through the suction path, and between the upper half and the lower half of the outer peripheral side member on the cavity side. A disc manufacturing method in which the gap is limited to 30 μm or less when the resin is filled.