JP3838729B2

JP3838729B2 - Side pressure cutting device

Info

Publication number: JP3838729B2
Application number: JP04682697A
Authority: JP
Inventors: 憲司山口; 一彰高木; 隆規長谷川
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 1997-03-03
Filing date: 1997-03-03
Publication date: 2006-10-25
Anticipated expiration: 2017-03-03
Also published as: JPH10245239A

Description

【０００１】
【発明の属する技術分野】
本発明は、工作物を側圧により切断する装置であり、特にレンズ等のガラス光学素子をプレスにより成形する場合に使用する工作物、例えばロッド状の長尺ガラスを切断し、高品質の切断面が要求され且つ量産に適した切断方法を必要とする分野で利用される側圧切断装置に関するものである。
【０００２】
【従来の技術】
従来から、非球面ガラスレンズの大量生産に適した成形工法による非球面ガラスレンズ量産技術が確立され、今日に至っている。このようなガラスレンズの成形で使用される光学素子素材は、研磨，ボールあるいは研磨円柱形状のものがほとんどである。
【０００３】
この円柱形状の光学素子素材の加工方法として、棒材を切断し、研磨，ラップ，ポリッシュ加工することにより両端面が鏡面である光学素子素材を得る従来からの加工方法に対して、近年では、側圧による材料の破壊を利用した新しい加工法が提案されている。
【０００４】
この新しい加工法は、加工において切り屑や騒音を発生せず、加工に要する時間もエネルギーも僅少で、また加工の際の側圧は、被加工物の大きさには関係せず一定値で、しかも切断面が平滑で、ガラスやセラミックスでは鏡面であるなど、従来の加工法には見られない多くの利点を持つ。
【０００５】
このような側圧切断法について、図６に示す加工装置を用いて説明する。
この加工装置は、図示するように、昇圧穴１２を持つ圧力容器１１と、圧力容器１１内に設けられた金属部材２８ａと、１回の切断個数分の長さの側圧伝達筒３の両端に設けられた一対の圧力シール部材２７ａ、２７ｂと、昇圧穴１２から一対の圧力シール部材２７ａ、２７ｂ間の圧力容器１１内に加圧媒体を供給する圧力発生装置（図は省略）と、一方の圧力シール部材２７ｂに当接している金属部材２８ｂとから構成されている。
【０００６】
棒状の工作物１には予め条痕２が設けられており、この工作物１は条痕２が昇圧穴１２に対向する位置まで圧力容器１１の側圧伝達筒３内に挿入される。次いで圧力発生装置（図は省略）から加圧媒体である作動油２２が昇圧穴１２から圧力容器１１内に導入されると、工作物１において、その表面には側圧伝達筒３を介して圧縮応力が発生し、中心部には引張応力が発生する。
【０００７】
工作物１の内部に発生する引張応力は加圧力に比例して大きくなり、その引張応力が工作物１の引張強さ以上になると、その時点で、工作物１は破断して切断され、この際に側圧伝達筒３内に位置する条痕２から各々時間差はあるものの、ほぼ同時に切断される。また工作物１と側圧伝達筒３の間には圧力媒体４を充填しておくとよい。
【０００８】
また、他の側圧切断法としては、図７に示すように、特開平７ー１３２５００号公報などにも開示されているストッパリング方式がある。このストッパリング方式は、図示するように、工作物１と圧力シール部材２９とが直接接触することを阻止するとともに、圧力シール部材２９が破損するのを防止するため、工作物１と圧力シール部材２９との間に金属部材３０を設けており、工作物１である棒材にかかる軸方向の引張力と同棒材の径方向の押圧力とにより１つの圧力シール部材２９が変形しながら、棒材を複数個に切断する方法である。
【０００９】
【発明が解決しようとする課題】
しかしながら上記のようなストッパリング方式による従来の側圧切断装置では、通常、昇圧と減圧が負荷されるディスキング法が用いられ、このディスキング法では、図８に示すように、圧力シール部材２９が側圧伝達筒３の径方向３１あるいは軸方向３２へ伸縮を繰り返すことによって、気密性を保つために必要な圧力シール部材２９や側圧伝達筒３の両端の端面３３を劣化させてしまう。
【００１０】
このような昇圧と減圧を繰り返した圧力シール部材２９の損傷発生状況を観察すると、圧力容器本体穴部３４と金属部材３０の軸方向のクリアランス間に挟まれたはみ出し傷と、金属部材３０と側圧伝達筒３との間の内周方向の隙間に挟まれたはみ出し傷とが残っていたり、また、側圧伝達筒３には、切断された光学素子素材が圧力容器１１から排出される際に同素材の切断エッジで削れたと思われるスクラッチ傷が生じていたりする。
【００１１】
この結果、側圧伝達筒３と圧力シール部材２９とのクリアランスが局部的に変わるため、徐々に切断性が低下し、最悪の場合、昇圧中にこの傷から側圧伝達筒３が破断してしまい、これらの消耗部材が劣化し気密性が低下した場合、絶えず新しい部材に交換しなければならず、量産性向上に対して大きな妨げとなってしまうという問題点を有していた。
【００１２】
また、条痕のついた工作物１は、切断前に側圧伝達筒３内に嵌入されるが、側圧伝達筒３の両端付近で切断された光学素子ほど切断面が平滑とならずに凹凸が生じるいわゆるうねり量が大きくなってしまい、光学素子の各々に重量ばらつきが発生するという問題点も有していた。
【００１３】
特に、うねり量は、側圧伝達筒３の両端近傍で切断された光学素子素材に発生しやすく、しかも工作物１の直径あるいは切断厚みによって異なり、外径が大きく切断厚みが薄いほど、各々の光学素子素材の重量精度や外観精度を下げるという悪影響を及ぼしてしまう。
【００１４】
加えて、側圧伝達筒３の両端近傍で切断された光学素子素材は、側圧伝達筒３の中央付近と同じ荷重で且つ均等な距離で条痕を設けたにもかかわらず、未切断あるいは外観不良が生じやすいという問題点をも有していた。
【００１５】
本発明は、上記従来の切断技術における問題点を解決するもので、ディスキング法において、指定した各々の断面で確実に同時切断することができるとともに、圧力シール部材や側圧伝達筒などの消耗部材の耐久性を大幅に向上することができ、工作物を無駄なく使い切ることが可能で、重量ばらつきの少ない高品質の光学素子素材を得ることができる側圧切断装置を提供する。
【００１６】
【課題を解決するための手段】
上記課題を解決するために、本発明の側圧切断装置は、一方の圧力シール部材が工作物の軸方向の気密性を確保し、もう一方の圧力シール部材が径方向の気密性を確保して、工作物の軸方向と径方向へ抜けようとする圧力をそれぞれ分割シールし、全体の気密性を向上することを特徴とする。
【００１８】
更に、工作物と同等の外径をもった棒状の金属部材を、側圧伝達筒の少なくとも片端から任意の距離だけ嵌入し、その状態で側圧を付加することにより応力切断することを特徴とする。
【００１９】
以上により、ディスキング法において、指定した各々の断面で確実に同時切断することができるとともに、圧力シール部材や側圧伝達筒などの消耗部材の耐久性を大幅に向上することができ、工作物を無駄なく使い切ることが可能で、重量ばらつきの少ない高品質の光学素子素材を得ることができる。
【００２０】
【発明の実施の形態】
本発明の請求項１に記載の側圧切断装置は、脆性材料からなる棒状で外周面に条痕が形成された工作物の前記外周面を覆う側圧伝達筒と、前記側圧伝達筒の両筒端における前記工作物の周囲に配置されかつ前記側圧伝達筒の少なくとも片側の筒端には複数が配置された圧力シール部材と、前記圧力シール部材をそれぞれ前記工作物に接触しない状態で保持するための金属部材と、前記金属部材を介して前記圧力シール部材を加圧変形させるための加圧手段と、前記側圧伝達筒と前記圧力シール部材と前記金属部材と加圧手段とを納める圧力容器とからなり、前記複数配置された側の圧力シール部材の少なくとも一つは、棒状の工作物の軸方向に抜けようとする圧力をシールするために配置し、他の圧力シール部材の少なくとも一つは、前記棒状の工作物の径方向に抜けようとする圧力をシールするために配置し、前記加圧手段により前記圧力シール部材が加圧変形された状態で、前記工作物の条痕に側圧を負荷することにより、前記工作物を応力切断する構成とする。
【００２２】
請求項２に記載の側圧切断装置は、請求項１に記載の側圧伝達筒は、工作物よりもヤング率の小さい材料で形成した構成とする。
これらの構成によると、一方の圧力シール部材が工作物の軸方向の気密性を確保し、もう一方の圧力シール部材が径方向の気密性を確保して、工作物の軸方向と径方向へ抜けようとする圧力をそれぞれ分割シールし、全体の気密性を向上する。
【００２６】
請求項３に記載の側圧切断装置は、請求項１または請求項２に記載の側圧切断装置であって、前記棒状の工作物の少なくとも片端に配置され前記棒状の工作物と同等の外径をもった棒状金属部材を設けた構成とする。
【００２７】
請求項４に記載の側圧切断装置は、請求項３に記載の棒状金属部材は、切断過程において少なくとも側圧負荷時には、側圧伝達筒に嵌合するように配置した構成とする。
【００２８】
これらの構成によると、工作物と同等の外径をもった棒状の金属部材を、側圧伝達筒の少なくとも片端から任意の距離だけ嵌入し、その状態で側圧を付加することにより応力切断する。
【００２９】
以下、本発明の実施の形態を示す側圧切断装置について、図面を参照しながら具体的に説明する。
（実施の形態１）
図１は本実施の形態１の側圧切断装置の構成を示す断面図である。この側圧切断装置は棒状の工作物１の切断に使用するものである。
【００３０】
側圧切断装置により工作物１を切断する際には、その切断に先立ち、予め工作物１の外周表面の切断位置上に位置せしめた圧子（図は省略）を使用し、図１に示すように、工作物１の切断位置の外周表面上に容易に切断を誘起するための条痕２を設けなければならない。この条痕２は、工作物１の外周表面に長さ方向と直角をなす角度で任意の設定距離毎に局部的に設けられる。
【００３１】
条痕２のついた棒状の工作物１の側面に側圧を加える場合について説明する。図１において、２は切断面を指定するために予め工作物１の外周表面に設けた複数個の条痕である。工作物１は圧力媒体４を介して側圧伝達筒３に嵌入されており、工作物１と側圧伝達筒３とのクリアランスは数十μｍである。側圧伝達筒３の両端には、軸方向圧力シール部材５と径方向圧力シール部材６とが各々配置されており、また軸方向圧力シール部材５と径方向圧力シール部材６とは、第１の金属部材７および第２の金属部材８にそれぞれ嵌入されている。これらの軸方向圧力シール部材５と径方向圧力シール部材６は、昇圧時の気密性を高めるため、保持部材９が加圧手段（図は省略）によって第１の金属部材７側へ一定距離だけ移動されることにより、加圧変形させられる。
【００３２】
軸方向圧力シール部材５は、棒状の工作物１の軸方向へ抜けようとする圧力をシールするために配置され、また径方向圧力シール部材６は、工作物１の径方向に抜けようとする圧力をシールするために配置されている。かかる状態において、工作物１の周囲で第１の金属部材７と第２の金属部材８に嵌入された４個の軸方向圧力シール部材５および径方向圧力シール部材６によって挟まれた区間の側圧伝達筒３の外周表面および圧力容器１１の内周部をシールすることが可能で、圧力室１０を構成すことができる。そこで、圧力容器１１の圧力室１０に昇圧穴１２を通じて油圧装置（図は省略）から作動油２２を流し込みながら、工作物１の外周表面に均等な側圧２１を加えることができる。
【００３３】
以下、実施の形態１の側圧切断装置における具体的な条件の説明を加える。
検討に使用した工作物１は、ヤング率１．０３×１０⁴ ｋｇｆ／ｍｍ² 、外径７ｍｍの中実円筒の光学ガラス棒で、レンズ成形用として用いられる。工作物１に切断面を指定するための条痕２は、圧子（図は省略）によって刻印される。使用した工作物１には、その外周表面の軸方向に３ｍｍの均等間隔で１０００ｇ以下の荷重を加えて条痕２を１３箇所設けた。この時、条痕２の長さは３５０μｍで、全て同等の形状である。
【００３４】
図１に示す装置において、条痕２のついた工作物１は、中空円筒の形状をしたメタクリル樹脂製の側圧伝達筒３に嵌入し、工作物１と側圧伝達筒３の間に封入した圧力媒体４は一般に知られている油脂を用いた。側圧伝達筒３の材料であるメタクリル樹脂のヤング率は、３．１ｋｇｆ／ｍｍ² で工作物１のヤング率の３０分の１程度である。また、側圧伝達筒３の長さを４０ｍｍとし、軸方向圧力シール部材５は線径１．２ｍｍのリング状ゴムで、径方向圧力シール部材６は線径１．５ｍｍのリング状ゴムで、第１の金属部材７および第２の金属部材８の所定位置に、それぞれ嵌入されている。
【００３５】
保持部材９が第１の金属部材７側へ１ｍｍ程度移動して第２の金属部材８に圧接することにより、軸方向および径方向の各圧力シール部材５，６が圧縮変形して、圧力室１０内の気密性を高めている。第１の金属部材７と第２の金属部材８は、炭素工具鋼を用いた。また、工作物１と第１の金属部材７や第２の金属部材８の各内径とのクリアランスは、側圧伝達筒３とのクリアランスとほぼ同じになるよう仕上げられている。
【００３６】
以上により、油圧による側圧２１を負荷する昇圧時には、従来方式の圧力シール部材では、工作物１の軸と径の２方向で気密性を保持しなければならず、Ｐ＝９ｋｇｆ／ｍｍ² の設定で全ての条痕２を通る横断面で鏡面が得られる条件下で昇圧，減圧を繰り返した場合、１５０回前後で昇圧不可能、すなわち圧力室１０の気密性を保つことができなかったが、上記のように、圧力シール部材として軸方向および径方向の各圧力シール部材５、６を工作物１の軸方向と径方向に分けてそれぞれ個別に設けて構成した場合、各々が一方向のみ気密性を保持すればよいこととなり、その結果、前記した切断条件での繰り返し昇圧，減圧の回数として、従来方式の４倍である６００回以上にわたって圧力室１０の気密性を保持することが可能となり、また、切断で得られた光学素子素材は品質的に問題のないレベルであった。
【００３７】
なお、図９に、実施の形態１の側圧切断装置による側圧切断によって得られた光学素子素材を加熱，加圧，冷却することによって成形された光学素子２３を示す。この光学素子２３は、ビデオムービー用レンズの一つとして使用され、片面が非球面で反対面が球面の両面凸形状をなしている。成形で使用される第１の成形型２４および第２の成形型２５は、それぞれ転写面が所望の凹形状に加工されており、胴型２６の上下内径部に各々嵌合されている。成形工程を経て得られた光学素子２３の転写精度は、他形状の光学素子素材を成形した時と何ら変わることがなく、光学特性上問題のない性能であった。
【００３８】
以上の実施の形態１の側圧切断装置による具体的な作動結果により、本発明の側圧切断装置による作用および効果が実証された。
なお、上記実施の形態１の側圧切断装置において、側圧伝達筒３は、射出成形あるいは切削のどちらによる加工品であっても切断する工作物１の材質には関係なく、メタクリル樹脂程度のヤング率を持つ材質であれば、同様の効果が得られる。また、それぞれの圧力シール部材５、６は、断面形状が円形状以外でも実施することは可能である。加えて、作動条件に応じて側圧Ｐ値，昇圧時間，あるいは設定圧力保持時間に変化を加えて実施することも可能である。
（実施の形態２）
図２は本実施の形態２の側圧切断装置の構成を示す断面図である。この側圧切断装置も実施の形態１の側圧切断装置と同様に、棒状の工作物１の切断に使用するものである。
【００３９】
この側圧切断装置においては、バックアップ部材１３が、側圧伝達筒３の両端に配置された第３の金属部材１５および第４の金属部材１６のそれぞれと圧力シール部材１４の低圧面側との間に、圧力シール部材１４を保護するために配置されている。このバックアップ部材１３は、保持部材９が加圧手段（図は省略）によって第３の金属部材１５側へ一定距離だけ移動されることにより、加圧変形させられ、その変形により工作物１の外周表面に挟着する。
【００４０】
図３は、バックアップ部材１３を配置した実施の形態２の側圧切断装置において、側圧２１を負荷した場合の圧力シール部材１４の変形状態を示す概略断面図である。
【００４１】
図２において、保持部材９を加圧手段によって第３の金属部材１５側へ約１ｍｍ移動して第４の金属部材１６に対して圧接した状態として、油圧による側圧２１を負荷した場合、図３に示すように、圧力シール部材１４は、圧力室１０の気密性を保ちながら、工作物１の低圧側にあたる軸方向と径方向に逃げようとするが、バックアップ部材１３は圧力シール部材１４のムシレやネジレなどの損傷を防止して、圧力シール部材１４の寿命を長く保つという効果を有する。特に径方向に逃げようとする圧力は、バックアップ部材１３の内フランジ部内周面を工作物１の外周表面に挟着させる。
【００４２】
この結果、工作物１の側圧伝達筒３内への嵌入が未完全である場合に、従来方式に見られたような側圧伝達筒３の両端付近に必ず存在する工作物１の切断性の劣化は、バックアップ部材１３の内フランジ内周面が、側圧伝達筒３の両端付近における工作物１への側圧不足を補うことによって、油圧による側圧２１を必要以上に上げることなく、重量ばらつきの少ない、高品質な光学素子素材を確実に得ることができる。
【００４３】
以下、実施の形態２の側圧切断装置における具体的な条件の説明を加える。
検討に使用した工作物１は、ヤング率１．０３×１０⁴ ｋｇｆ／ｍｍ² 、外径７ｍｍの中実円筒の光学ガラス棒で、実施の形態１の場合と同一である。また、工作物１の外周表面に設けられた条痕２も同一形状である。
【００４４】
図２に示す装置において、条痕２のついた工作物１は、中空円筒の形状をしたメタクリル樹脂製の側圧伝達筒３に嵌入している。バックアップ部材１３は、ヤング率７ｋｇｆ／ｍｍ² であり、メタクリル樹脂のヤング率の２倍程度高い値を有しているが、材料の伸びはメタクリル樹脂の３倍の約１５％である。また、第３の金属部材１５と第４の金属部材１６のそれぞれにおける所定位置には、圧力シール部材１４とバックアップ部材１３とが配置されている。圧力シール部材１４は、線径１．５ｍｍのリング状ゴムで、実施の形態１の側圧切断装置で用いた径方向圧力シール部材６と同一品である。第３の金属部材１５および第４の金属部材１６は、第１の金属部材７および第２の金属部材８と同じ材質で作られている。
【００４５】
かかる状態において、条痕２のついた工作物１は、側圧Ｐ＝８ｋｇｆ／ｍｍ² によって、側圧伝達筒３に嵌入された部分において側圧伝達筒３の両端付近を含む全ての条痕２を通る横断面で切断が発生し、その切断で得られた光学素子素材は高品質なものであった。
【００４６】
以上の実施の形態２の側圧切断装置による具体的な作動結果により、本発明の側圧切断装置による作用および効果が実証された。
なお、上記実施の形態２の側圧切断装置においては、そのバックアップ部材１３の内フランジ部の形状は、工作物１の外周面に側圧を負荷できればどのような形状でも可能である上、工作物１の径方向のみでなく、軸方向へ異なった形状のバックアップ部材を追加配置しても、圧力シール部材１４の寿命を長くするという同様の効果が得られる。
【００４７】
また、条痕２の設定距離が変更された場合においても容易に対応可能となり、側圧伝達筒３の長さを変える必要はない。更に、実施の形態１と２を考慮し、複合した構成も当然実施可能である。
（実施の形態３）
図４は、実施の形態３の側圧切断装置の構成を示す断面図である。この側圧切断装置も実施の形態１および実施の形態２の側圧切断装置と同様に、棒状の工作物１の切断に使用するものである。
【００４８】
この側圧切断装置においては、棒状の第５の金属部材１７が、工作物１の片端にお互いの端面が当接するように配置され、この第５の金属部材１７は、工作物１と同等の外径で外観も近似しているものの、脆性材料である工作物１とは異なった性質を持った部材で、特に靱性に富む一般的な金属を用いる。側圧伝達筒３の両端に配置された第６の金属部材１８および第７の金属部材１９には、それぞれに同じ圧力シール部材１４が嵌入され、これらの圧力シール部材１４は、昇圧時の気密性を高めるため、保持部材９が加圧手段（図は省略）によって第６の金属部材１８側へ一定距離だけ移動されることにより、加圧変形させられる。側圧伝達筒３内に任意の距離だけ嵌入された第５の金属部材１７は、工作物１と共に油圧による側圧２１が負荷されると、工作物１は条痕２のついた指定された断面に沿って切断されるものの、第５の金属部材１７は破断することはない。
【００４９】
また、図５に示すように、側圧伝達筒３よりも短い工作物１を切断する場合には、工作物１の第５の金属部材１７と接する反対面側に第８の金属部材２０を配置し、その第８の金属部材２０を、第５の金属部材１７とにより工作物１を挟持するように、側圧伝達筒３内に嵌入する。第８の金属部材２０は、第５の金属部材１７と同様、工作物１と同等の外径で、一般的な金属を用いているのに加えて、規定数の切断が終了した工作物１を排出する機能も備えている。
【００５０】
これらの結果より、従来方式にあるような側圧伝達筒３の両端付近で切断される工作物１の切断性の劣化などの欠点に対して、第５の金属部材１７および第８の金属部材２０が擬製工作物の役割を果たすことにより、肝心の工作物１が側圧伝達筒３の中央付近に位置するため、重量ばらつきの少ない高品質な光学素子素材を確実に得ることができる。
【００５１】
また、切断を繰り返すうちに側圧伝達筒３より短くなった工作物１は、従来方式では廃棄処理するしかなかったが、工作物１を無駄なく利用することができる。更に、２個分あるいは３個分など未切断の工作物１だけを集めて上記した方式を用いて切断しても、無駄なく重量ばらつきの少ない且つ高品質な光学素子素材を得ることができる。
【００５２】
以下、実施の形態３の側圧切断装置における具体的な条件の説明を加える。
検討に使用した工作物１は、上記実施の形態１および実施の形態２の側圧切断装置で使用したものと同一で、ヤング率１．０３×１０⁴ ｋｇｆ／ｍｍ² であり、外径７ｍｍの中実円筒の光学ガラス棒である。
【００５３】
図４に示す装置において、条痕２のついた工作物１は、中空円筒の形状をしたメタクリル樹脂製の側圧伝達筒３に嵌入している。第５の金属部材１７は、炭素工具鋼で、ヤング率は８０ｋｇｆ／ｍｍ² 前後のものを用いた。また、図５に示す装置において、第８の金属部材２０は、第５の金属部材１７の長さの異なる同等品を用いた。工作物１の外周表面に設けられた条痕２も同一形状である。側圧切断装置の主要な構成部材および各手段において、従来方式と何ら変わるところはない。第６の金属部材１８や第７の金属部材１９も、第１の金属部材７や第２の金属部材８と同じ材質で作られている。
【００５４】
かかる状態において、条痕２のついた工作物１は、側圧Ｐ＝８．５ｋｇｆ／ｍｍ² である１回の昇圧で工作物１の先端部分の３個分を切断し第５の金属部材１７に置き換えて１０個分を切断した後、余分になった工作物１は、第５の金属部材１７と第８の金属部材２０を用いて再切断を行なった。
【００５５】
その結果、全ての条痕２を通る横断面で切断が発生し、その際の重量ばらつきを、従来方式で切断した光学素子素材と比べて、標準偏差値で約３４％、分散値で５６％向上することができた。
【００５６】
この様に、上記構成における実施の形態３の側圧切断装置による具体的な作動結果により、本発明の側圧切断装置による作用および効果が実証された。
なお、本実施の形態３の側圧切断装置に示した第５の金属部材１７や第８の金属部材２０は、実施の形態１、２および３を考慮し、複合した構成も当然可能である。また、いずれの実施の形態においても、工作物１は光学ガラス棒材とは限らず、脆性材料であればいずれも適応可能であることは言うまでもない。
【００５７】
【発明の効果】
以上のように本発明によれば、一方の圧力シール部材が工作物の軸方向の気密性を確保し、もう一方の圧力シール部材が径方向の気密性を確保して、工作物の軸方向と径方向へ抜けようとする圧力をそれぞれ分割シールし、全体の気密性を向上することができる。
【００５９】
更に、本発明によれば、工作物と同等の外径をもった棒状の金属部材を、側圧伝達筒の少なくとも片端から任意の距離だけ嵌入し、その状態で側圧を付加することにより応力切断することができる。
【００６０】
そのため、ディスキング法において、切断の際に、切り屑や騒音を伴わず、必要以上の時間とエネルギーを一切不要とし、１回の側圧を負荷するだけで指定された複数個の切断を確実に発生して、指定した各々の断面で確実に同時切断することができるとともに、圧力シール部材や側圧伝達筒などの消耗部材の耐久性を大幅に向上することができ、工作物を無駄なく使い切ることが可能となり、高い生産性が得られ、安価で重量ばらつきの少ない高品質の光学素子素材を大量に得ることができる。
【図面の簡単な説明】
【図１】本発明の実施の形態１における側圧切断装置の断面図
【図２】本発明の実施の形態２における側圧切断装置の断面図
【図３】同実施の形態２における側圧Ｐを負荷した場合の説明図
【図４】本発明の実施の形態３における側圧切断装置の断面図
【図５】同実施の形態３における側圧切断装置の他方の断面図
【図６】従来の第１の側圧切断装置の断面図
【図７】従来の第２の側圧切断装置の断面図
【図８】同従来例における側圧Ｐを負荷した場合の説明図
【図９】光学素子を成形によって得る場合の説明図
【符号の説明】
５軸方向圧力シール部材
６径方向圧力シール部材
７第１の金属部材
８第２の金属部材
９保持部材
１０圧力室
１３バックアップ部材
１４圧力シール部材
１５第３の金属部材
１６第４の金属部材
１７第５の金属部材
１８第６の金属部材
１９第７の金属部材
２０第８の金属部材
２１側圧[0001]
BACKGROUND OF THE INVENTION
The present invention is an apparatus for cutting a workpiece by lateral pressure, and in particular, cuts a workpiece, for example, a rod-shaped long glass, used when a glass optical element such as a lens is molded by a press to obtain a high quality cut surface. The present invention relates to a side pressure cutting device used in a field that requires a cutting method suitable for mass production.
[0002]
[Prior art]
Conventionally, mass production technology of aspherical glass lenses by a molding method suitable for mass production of aspherical glass lenses has been established and has reached today. Most of the optical element materials used for molding such glass lenses are polished, ball or polished cylindrical.
[0003]
As a processing method of this cylindrical optical element material, in recent years, in contrast to the conventional processing method of obtaining an optical element material whose both end surfaces are mirror surfaces by cutting, polishing, lapping and polishing a bar material, A new processing method that utilizes the destruction of materials by lateral pressure has been proposed.
[0004]
This new processing method does not generate chips or noise during processing, requires little time and energy for processing, and the side pressure during processing is constant regardless of the size of the workpiece, Moreover, it has many advantages not seen in conventional processing methods, such as a smooth cut surface and a mirror surface in glass or ceramics.
[0005]
Such a lateral pressure cutting method will be described with reference to a processing apparatus shown in FIG.
As shown in the figure, this processing apparatus includes a pressure vessel 11 having a pressure hole 12, a metal member 28a provided in the pressure vessel 11, and both ends of a side pressure transmission cylinder 3 having a length corresponding to the number of cuts. A pair of pressure seal members 27a and 27b provided, a pressure generator (not shown) for supplying a pressurized medium into the pressure vessel 11 between the pair of pressure seal members 27a and 27b from the pressure increase hole 12, The metal member 28b is in contact with the pressure seal member 27b.
[0006]
The bar-shaped workpiece 1 is provided with the striations 2 in advance, and the workpiece 1 is inserted into the side pressure transmission cylinder 3 of the pressure vessel 11 until the striations 2 are opposed to the pressure increase holes 12. Next, when hydraulic oil 22 as a pressurizing medium is introduced from the pressure generating device (not shown) into the pressure vessel 11 through the pressurizing hole 12, the surface of the workpiece 1 is compressed via the side pressure transmission cylinder 3. Stress is generated, and tensile stress is generated in the center.
[0007]
The tensile stress generated inside the workpiece 1 increases in proportion to the applied pressure. When the tensile stress exceeds the tensile strength of the workpiece 1, the workpiece 1 is broken and cut at this point. At this time, the streaks 2 located in the side pressure transmission cylinder 3 are cut at almost the same time, although there are time differences. Further, the pressure medium 4 may be filled between the workpiece 1 and the side pressure transmission cylinder 3.
[0008]
As another lateral pressure cutting method, as shown in FIG. 7, there is a stoppering method disclosed in JP-A-7-132500. As shown in the figure, this stopper ring system prevents the workpiece 1 and the pressure seal member 29 from coming into direct contact and prevents the pressure seal member 29 from being damaged. 29, a metal member 30 is provided, and while one pressure seal member 29 is deformed by the axial tensile force applied to the bar which is the workpiece 1 and the radial pressing force of the bar, This is a method of cutting a bar material into a plurality of pieces.
[0009]
[Problems to be solved by the invention]
However, in the conventional side pressure cutting device using the stopper ring system as described above, a disking method in which pressure increase and pressure reduction are applied is usually used. In this disking method, as shown in FIG. By repeatedly expanding and contracting in the radial direction 31 or the axial direction 32 of the side pressure transmission cylinder 3, the pressure seal members 29 and the end surfaces 33 at both ends of the side pressure transmission cylinder 3 necessary for maintaining airtightness are deteriorated.
[0010]
When observing the occurrence of damage to the pressure seal member 29 in which pressure increase and pressure reduction are repeated, a protruding flaw sandwiched between the pressure vessel main body hole 34 and the axial clearance of the metal member 30, the metal member 30 and the side pressure A protruding flaw that is sandwiched in a gap in the inner circumferential direction with the transmission cylinder 3 remains, and the side pressure transmission cylinder 3 is the same when the cut optical element material is discharged from the pressure vessel 11. There are scratches that appear to have been scraped off at the cutting edge of the material.
[0011]
As a result, since the clearance between the side pressure transmission cylinder 3 and the pressure seal member 29 changes locally, the cutting performance gradually decreases, and in the worst case, the side pressure transmission cylinder 3 breaks from this flaw during pressurization, When these consumable members deteriorate and the airtightness decreases, there is a problem that they must be constantly replaced with new members, which greatly hinders mass productivity improvement.
[0012]
In addition, the work 1 with the streak is inserted into the lateral pressure transmission cylinder 3 before cutting, but the cut surface is not smooth and uneven as the optical elements cut in the vicinity of both ends of the lateral pressure transmission cylinder 3. The amount of so-called undulation that occurs is increased, and there is a problem in that weight variation occurs in each optical element.
[0013]
In particular, the amount of undulation is likely to occur in the optical element material cut in the vicinity of both ends of the side pressure transmission cylinder 3, and varies depending on the diameter or cutting thickness of the workpiece 1, and the larger the outer diameter and the thinner the cutting thickness, This adversely affects the weight accuracy and appearance accuracy of the element material.
[0014]
In addition, the optical element material cut in the vicinity of both ends of the side pressure transmission cylinder 3 is not cut or has an appearance defect despite the fact that the striations are provided at the same load and at an equal distance as the vicinity of the center of the side pressure transmission cylinder 3. It also had the problem that it was easy to occur.
[0015]
The present invention solves the above-mentioned problems in the conventional cutting technology, and in the discing method, it can be surely cut simultaneously at each specified cross section, and is a consumable member such as a pressure seal member or a side pressure transmission cylinder. There is provided a lateral pressure cutting device that can greatly improve the durability of the apparatus, can use the workpiece without waste, and can obtain a high-quality optical element material with little weight variation.
[0016]
[Means for Solving the Problems]
In order to solve the above-described problem, the lateral pressure cutting device of the present invention has one pressure seal member ensuring the airtightness in the axial direction of the workpiece and the other pressure seal member ensuring the airtightness in the radial direction. In addition, it is characterized in that the pressure to escape in the axial direction and the radial direction of the workpiece is divided and sealed to improve the overall airtightness.
[0018]
Further, the present invention is characterized in that a rod-shaped metal member having an outer diameter equivalent to that of a workpiece is inserted at an arbitrary distance from at least one end of the side pressure transmission cylinder, and stress is cut by applying a side pressure in this state.
[0019]
As described above, in the discing method, it is possible to reliably cut simultaneously at each specified cross section, and to greatly improve the durability of consumable members such as a pressure seal member and a side pressure transmission cylinder. A high-quality optical element material that can be used up without waste and has little weight variation can be obtained.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The lateral pressure cutting device according to claim 1 of the present invention is a rod-like shape made of a brittle material and has a lateral pressure transmission cylinder that covers the outer circumferential surface of a workpiece having a streak formed on the outer circumferential surface, and both cylinder ends of the lateral pressure transmission cylinder. And a plurality of pressure seal members disposed around at least one side of the side pressure transmitting cylinder, and holding the pressure seal members in a state of not contacting the workpiece. A metal member, a pressurizing means for pressurizing and deforming the pressure seal member via the metal member, and a pressure vessel containing the side pressure transmission cylinder, the pressure seal member, the metal member, and the pressurizing means. Become At least one of the plurality of arranged pressure seal members is arranged to seal the pressure to be released in the axial direction of the rod-shaped workpiece, and at least one of the other pressure seal members is the rod-shaped workpiece. Placed in order to seal the pressure of trying to escape in the radial direction of the workpiece, In a state where the pressure seal member is pressurized and deformed by the pressurizing means, the workpiece is stress-cut by applying a lateral pressure to the striations of the workpiece.
[0022]
Claim 2 The side pressure cutting device according to claim 1 The described side pressure transmission cylinder is formed of a material having a Young's modulus smaller than that of the workpiece.
According to these configurations, one pressure seal member secures the airtightness in the axial direction of the workpiece, and the other pressure seal member secures the airtightness in the radial direction, so that the axial direction and the radial direction of the workpiece are secured. The pressure to be removed is divided and sealed to improve the overall airtightness.
[0026]
Claim 3 The lateral pressure cutting device according to claim 1 is a Or claim 2 The side pressure cutting device according to claim 1, wherein a bar-shaped metal member having an outer diameter equivalent to that of the bar-shaped workpiece is provided at least at one end of the bar-shaped workpiece.
[0027]
Claim 4 The side pressure cutting device according to claim 3 The bar-shaped metal member described in (1) is configured to be fitted to the side pressure transmission cylinder at least when the side pressure is applied in the cutting process.
[0028]
According to these configurations, a rod-shaped metal member having an outer diameter equivalent to that of the workpiece is inserted by an arbitrary distance from at least one end of the side pressure transmission cylinder, and stress is cut by applying the side pressure in this state.
[0029]
Hereinafter, a side pressure cutting device showing an embodiment of the present invention will be specifically described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a cross-sectional view showing the configuration of the lateral pressure cutting device according to the first embodiment. This side pressure cutting device is used for cutting a bar-shaped workpiece 1.
[0030]
When the workpiece 1 is cut by the side pressure cutting device, an indenter (not shown) previously positioned on the cutting position on the outer peripheral surface of the workpiece 1 is used prior to the cutting, as shown in FIG. A streak 2 for easily inducing cutting must be provided on the outer peripheral surface of the workpiece 1 at the cutting position. The streak 2 is locally provided on the outer peripheral surface of the workpiece 1 at an angle that is perpendicular to the length direction at every set distance.
[0031]
The case where a lateral pressure is applied to the side surface of the rod-shaped workpiece 1 with the streak 2 will be described. In FIG. 1, reference numeral 2 denotes a plurality of streaks provided in advance on the outer peripheral surface of the workpiece 1 in order to designate a cut surface. The workpiece 1 is fitted into the side pressure transmission cylinder 3 via the pressure medium 4, and the clearance between the workpiece 1 and the side pressure transmission cylinder 3 is several tens of μm. An axial pressure seal member 5 and a radial pressure seal member 6 are respectively disposed at both ends of the side pressure transmission cylinder 3, and the axial pressure seal member 5 and the radial pressure seal member 6 are the first The metal member 7 and the second metal member 8 are respectively fitted. The axial pressure seal member 5 and the radial pressure seal member 6 are provided with a predetermined distance from the holding member 9 to the first metal member 7 side by the pressurizing means (not shown) in order to improve the airtightness at the time of pressurization. By being moved, it is deformed under pressure.
[0032]
The axial pressure seal member 5 is arranged to seal the pressure to be released in the axial direction of the rod-shaped workpiece 1, and the radial pressure seal member 6 is to be released in the radial direction of the workpiece 1. Arranged to seal pressure. In such a state, the side pressure of the section sandwiched by the four axial pressure seal members 5 and the radial pressure seal member 6 fitted around the first metal member 7 and the second metal member 8 around the workpiece 1. The outer peripheral surface of the transmission cylinder 3 and the inner peripheral part of the pressure vessel 11 can be sealed, and the pressure chamber 10 can be configured. Therefore, a uniform lateral pressure 21 can be applied to the outer peripheral surface of the workpiece 1 while flowing the hydraulic oil 22 from the hydraulic device (not shown) into the pressure chamber 10 of the pressure vessel 11 through the pressure hole 12.
[0033]
Hereinafter, specific conditions in the lateral pressure cutting device of the first embodiment will be described.
Workpiece 1 used for the study has a Young's modulus of 1.03 × 10 ^Four kgf / mm ² A solid cylindrical optical glass rod with an outer diameter of 7 mm, which is used for lens molding. A streak 2 for designating a cut surface on the workpiece 1 is imprinted by an indenter (not shown). The used workpiece 1 was provided with 13 streaks 2 by applying a load of 1000 g or less at an equal interval of 3 mm in the axial direction of the outer peripheral surface thereof. At this time, the length of the streak 2 is 350 μm and all have the same shape.
[0034]
In the apparatus shown in FIG. 1, a workpiece 1 with a streak 2 is fitted into a side pressure transmission cylinder 3 made of methacrylic resin having a hollow cylindrical shape, and the pressure enclosed between the workpiece 1 and the side pressure transmission cylinder 3. As the medium 4, generally known fats and oils were used. The Young's modulus of the methacrylic resin that is the material of the side pressure transmission cylinder 3 is 3.1 kgf / mm. ² Therefore, it is about 1/30 of the Young's modulus of the workpiece 1. The length of the side pressure transmission cylinder 3 is 40 mm, the axial pressure seal member 5 is a ring-shaped rubber having a wire diameter of 1.2 mm, and the radial pressure seal member 6 is a ring-shaped rubber having a wire diameter of 1.5 mm. The first metal member 7 and the second metal member 8 are respectively inserted into predetermined positions.
[0035]
When the holding member 9 moves about 1 mm toward the first metal member 7 and presses against the second metal member 8, the pressure seal members 5 and 6 in the axial direction and the radial direction are compressed and deformed, and the pressure chamber The airtightness in 10 is improved. Carbon tool steel was used for the first metal member 7 and the second metal member 8. Further, the clearance between the workpiece 1 and the inner diameters of the first metal member 7 and the second metal member 8 is finished to be substantially the same as the clearance with the side pressure transmission cylinder 3.
[0036]
As described above, at the time of pressurization in which the side pressure 21 is applied by hydraulic pressure, the pressure seal member of the conventional method must maintain airtightness in the two directions of the axis and the diameter of the workpiece 1, and P = 9 kgf / mm ² When pressure increase and decrease were repeated under the condition that the mirror surface was obtained in the cross section passing through all the striations 2 with the setting of 1, the pressure could not be increased around 150 times, that is, the airtightness of the pressure chamber 10 could not be maintained. However, as described above, when the pressure seal members 5 and 6 in the axial direction and the radial direction are separately provided separately in the axial direction and the radial direction of the workpiece 1 as described above, each of the pressure seal members is in one direction. As a result, the airtightness of the pressure chamber 10 can be maintained over 600 times, which is four times the conventional method, as the number of times of repeated pressure increase / decrease under the above-described cutting conditions. Further, the optical element material obtained by cutting was at a level with no problem in quality.
[0037]
FIG. 9 shows an optical element 23 formed by heating, pressurizing, and cooling an optical element material obtained by side pressure cutting by the side pressure cutting device of the first embodiment. This optical element 23 is used as one of the lenses for a video movie, and has a double-sided convex shape in which one surface is aspherical and the opposite surface is spherical. The first molding die 24 and the second molding die 25 used in molding each have a transfer surface processed into a desired concave shape, and are respectively fitted to the upper and lower inner diameter portions of the body die 26. The transfer accuracy of the optical element 23 obtained through the molding process did not change at all when the optical element material having another shape was molded, and the performance was satisfactory in terms of optical characteristics.
[0038]
The action and effect of the side pressure cutting device of the present invention have been verified by the specific operation results of the side pressure cutting device of Embodiment 1 described above.
In the lateral pressure cutting device according to the first embodiment, the lateral pressure transmission cylinder 3 has a Young's modulus comparable to that of a methacrylic resin regardless of the material of the workpiece 1 to be cut regardless of whether it is a processed product by injection molding or cutting. The same effect can be obtained if the material has. Each of the pressure seal members 5 and 6 can be implemented even if the cross-sectional shape is other than a circular shape. In addition, the side pressure P value, the pressure increase time, or the set pressure holding time can be changed depending on the operating conditions.
(Embodiment 2)
FIG. 2 is a cross-sectional view showing the configuration of the lateral pressure cutting device according to the second embodiment. This side pressure cutting device is also used for cutting the rod-shaped workpiece 1 in the same manner as the side pressure cutting device of the first embodiment.
[0039]
In this side pressure cutting device, the backup member 13 is interposed between each of the third metal member 15 and the fourth metal member 16 disposed at both ends of the side pressure transmission cylinder 3 and the low pressure surface side of the pressure seal member 14. , Arranged to protect the pressure seal member 14. The backup member 13 is deformed by pressurization when the holding member 9 is moved to the third metal member 15 side by the pressurizing means (not shown), and the outer periphery of the workpiece 1 is deformed by the deformation. Stick to the surface.
[0040]
FIG. 3 is a schematic cross-sectional view showing a deformed state of the pressure seal member 14 when the side pressure 21 is applied in the side pressure cutting device according to the second embodiment in which the backup member 13 is arranged.
[0041]
In FIG. 2, when the holding member 9 is moved about 1 mm toward the third metal member 15 by the pressurizing means and is pressed against the fourth metal member 16, a side pressure 21 due to hydraulic pressure is applied. As shown in FIG. 4, the pressure seal member 14 tries to escape in the axial direction and the radial direction corresponding to the low pressure side of the workpiece 1 while maintaining the airtightness of the pressure chamber 10. It has the effect of preventing the damage such as twisting and the like and keeping the life of the pressure seal member 14 long. Particularly, the pressure to escape in the radial direction causes the inner peripheral surface of the inner flange portion of the backup member 13 to be clamped to the outer peripheral surface of the workpiece 1.
[0042]
As a result, when the work 1 is not completely inserted into the side pressure transmission cylinder 3, the cutting performance of the work 1 always present near both ends of the side pressure transmission cylinder 3 as seen in the conventional method is deteriorated. The inner peripheral surface of the inner flange of the backup member 13 compensates for the shortage of the side pressure to the workpiece 1 in the vicinity of both ends of the side pressure transmission cylinder 3, so that the side pressure 21 due to the hydraulic pressure is not increased more than necessary, and the weight variation is small. A high-quality optical element material can be obtained reliably.
[0043]
Hereinafter, specific conditions in the lateral pressure cutting device of the second embodiment will be described.
Workpiece 1 used for the study has a Young's modulus of 1.03 × 10 ^Four kgf / mm ² A solid cylindrical optical glass rod having an outer diameter of 7 mm, which is the same as in the first embodiment. Further, the streak 2 provided on the outer peripheral surface of the workpiece 1 has the same shape.
[0044]
In the apparatus shown in FIG. 2, the workpiece 1 with the streak 2 is fitted in a methacrylic resin side pressure transmission cylinder 3 having a hollow cylindrical shape. The backup member 13 has a Young's modulus of 7 kgf / mm. ² Although it has a value about twice as high as the Young's modulus of methacrylic resin, the elongation of the material is about 15%, which is three times that of methacrylic resin. In addition, a pressure seal member 14 and a backup member 13 are disposed at predetermined positions in the third metal member 15 and the fourth metal member 16, respectively. The pressure seal member 14 is a ring-shaped rubber having a wire diameter of 1.5 mm, and is the same product as the radial pressure seal member 6 used in the lateral pressure cutting device of the first embodiment. The third metal member 15 and the fourth metal member 16 are made of the same material as the first metal member 7 and the second metal member 8.
[0045]
In such a state, the workpiece 1 with the streak 2 has a lateral pressure P = 8 kgf / mm. ² As a result, cutting occurs in the cross section passing through all the striations 2 including the vicinity of both ends of the side pressure transmission cylinder 3 in the portion inserted into the side pressure transmission cylinder 3, and the optical element material obtained by the cutting is of high quality Met.
[0046]
The action and effect of the side pressure cutting device of the present invention have been verified by the specific operation results of the side pressure cutting device of the second embodiment.
In the side pressure cutting device according to the second embodiment, the shape of the inner flange portion of the backup member 13 can be any shape as long as the side pressure can be applied to the outer peripheral surface of the workpiece 1. Even if backup members having different shapes in the axial direction as well as in the radial direction are additionally arranged, the same effect of extending the life of the pressure seal member 14 can be obtained.
[0047]
Further, even when the set distance of the streak 2 is changed, it is possible to easily cope with it, and it is not necessary to change the length of the side pressure transmission cylinder 3. Furthermore, in consideration of the first and second embodiments, a combined configuration can naturally be implemented.
(Embodiment 3)
FIG. 4 is a cross-sectional view illustrating a configuration of the lateral pressure cutting device according to the third embodiment. This side pressure cutting device is also used for cutting the bar-shaped workpiece 1 in the same manner as the side pressure cutting devices of the first and second embodiments.
[0048]
In this lateral pressure cutting device, a rod-like fifth metal member 17 is arranged so that the end surfaces of the fifth metal member 17 are in contact with one end of the workpiece 1, and the fifth metal member 17 is externally equivalent to the workpiece 1. Although it is similar in diameter and appearance, it is a member having properties different from those of the workpiece 1 which is a brittle material, and a general metal having particularly high toughness is used. The same pressure seal member 14 is fitted into each of the sixth metal member 18 and the seventh metal member 19 arranged at both ends of the side pressure transmission cylinder 3, and these pressure seal members 14 are airtight at the time of pressure increase. In order to increase the pressure, the holding member 9 is pressed and deformed by being moved by a predetermined distance toward the sixth metal member 18 side by a pressing means (not shown). When the fifth metal member 17 inserted into the side pressure transmission cylinder 3 at an arbitrary distance is loaded with the side pressure 21 by the hydraulic pressure together with the workpiece 1, the workpiece 1 has a specified cross section with the streak 2. Although it is cut along, the fifth metal member 17 does not break.
[0049]
Further, as shown in FIG. 5, when the workpiece 1 shorter than the side pressure transmission cylinder 3 is cut, the eighth metal member 20 is disposed on the opposite surface side of the workpiece 1 in contact with the fifth metal member 17. Then, the eighth metal member 20 is fitted into the side pressure transmission cylinder 3 so that the workpiece 1 is sandwiched by the fifth metal member 17. As with the fifth metal member 17, the eighth metal member 20 has an outer diameter equivalent to that of the workpiece 1 and uses a general metal. In addition, the eighth metal member 20 has finished a predetermined number of cuts. It also has a function to discharge the wastewater.
[0050]
From these results, the fifth metal member 17 and the eighth metal member 20 against the drawbacks such as deterioration of the cutting ability of the workpiece 1 cut near both ends of the side pressure transmission cylinder 3 as in the conventional method. However, since the essential workpiece 1 is located near the center of the lateral pressure transmission cylinder 3, a high-quality optical element material with little weight variation can be obtained with certainty.
[0051]
Further, the workpiece 1 that has become shorter than the side pressure transmission cylinder 3 while repeating the cutting can only be discarded in the conventional method, but the workpiece 1 can be used without waste. Furthermore, even if only uncut workpieces 1 such as two or three are collected and cut using the above-described method, a high-quality optical element material with little weight variation can be obtained without waste.
[0052]
Hereinafter, specific conditions in the lateral pressure cutting device of the third embodiment will be described.
The workpiece 1 used for the examination is the same as that used in the lateral pressure cutting device of the first embodiment and the second embodiment, and the Young's modulus is 1.03 × 10. ^Four kgf / mm ² It is a solid cylindrical optical glass rod having an outer diameter of 7 mm.
[0053]
In the apparatus shown in FIG. 4, the workpiece 1 with the streak 2 is fitted into a side pressure transmission cylinder 3 made of methacrylic resin having a hollow cylindrical shape. The fifth metal member 17 is carbon tool steel, and Young's modulus is 80 kgf / mm. ² The front and rear ones were used. In the apparatus shown in FIG. 5, the eighth metal member 20 is an equivalent product having a different length from the fifth metal member 17. The streak 2 provided on the outer peripheral surface of the workpiece 1 has the same shape. There is no difference from the conventional method in the main components and each means of the side pressure cutting device. The sixth metal member 18 and the seventh metal member 19 are also made of the same material as the first metal member 7 and the second metal member 8.
[0054]
In such a state, the workpiece 1 with the streak 2 has a lateral pressure P = 8.5 kgf / mm. ² After cutting the tip portion of the workpiece 1 by three pressures and replacing it with the fifth metal member 17 and cutting 10 pieces, the extra workpiece 1 is the fifth metal. Recutting was performed using the member 17 and the eighth metal member 20.
[0055]
As a result, cutting occurs in the cross section passing through all the streaks 2, and the weight variation at that time is about 34% in standard deviation value and 56% in dispersion value compared with the optical element material cut by the conventional method. I was able to improve.
[0056]
Thus, the action and effect of the lateral pressure cutting device of the present invention were verified by the specific operation results of the lateral pressure cutting device of Embodiment 3 in the above configuration.
Note that the fifth metal member 17 and the eighth metal member 20 shown in the lateral pressure cutting device according to the third embodiment can be combined with each other in consideration of the first, second, and third embodiments. In any of the embodiments, it is needless to say that the workpiece 1 is not limited to the optical glass rod, and any brittle material can be applied.
[0057]
【The invention's effect】
As above Book According to the invention, one pressure seal member secures the airtightness in the axial direction of the workpiece, and the other pressure seal member secures the airtightness in the radial direction so that the workpiece is removed in the axial direction and the radial direction. The pressure to be divided can be divided and sealed to improve the overall airtightness.
[0059]
In addition, book According to the invention, a bar-shaped metal member having an outer diameter equivalent to that of a workpiece can be inserted by an arbitrary distance from at least one end of the side pressure transmission cylinder, and stress cutting can be performed by applying the side pressure in that state. .
[0060]
Therefore, in the discing method, when cutting, there is no chip or noise, no unnecessary time and energy are required, and multiple specified cuts can be ensured by applying a single side pressure. It is possible to reliably cut simultaneously at each specified cross section, and the durability of consumable members such as pressure seal members and side pressure transmission cylinders can be greatly improved, so that the workpiece can be used up without waste. Thus, high productivity can be obtained, and a large amount of high-quality optical element material that is inexpensive and has little weight variation can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a lateral pressure cutting device according to Embodiment 1 of the present invention.
FIG. 2 is a sectional view of a lateral pressure cutting device according to a second embodiment of the present invention.
FIG. 3 is an explanatory diagram when a lateral pressure P is loaded in the second embodiment.
FIG. 4 is a cross-sectional view of a lateral pressure cutting device according to Embodiment 3 of the present invention.
FIG. 5 is another cross-sectional view of the lateral pressure cutting device according to the third embodiment.
FIG. 6 is a sectional view of a conventional first lateral pressure cutting device.
FIG. 7 is a sectional view of a conventional second side pressure cutting device.
FIG. 8 is an explanatory diagram when a side pressure P is applied in the conventional example.
FIG. 9 is an explanatory diagram when an optical element is obtained by molding.
[Explanation of symbols]
5 Axial pressure seal member
6 Radial pressure seal member
7 First metal member
8 Second metal member
9 Holding member
10 Pressure chamber
13 Backup material
14 Pressure seal member
15 Third metal member
16 Fourth metal member
17 Fifth metal member
18 Sixth metal member
19 Seventh metal member
20 Eighth metal member
21 Side pressure

Claims

A side pressure transmission cylinder that covers the outer circumferential surface of the workpiece and is formed of a brittle material with a streak formed on the outer circumferential surface, and the side pressure transmission cylinder that is disposed around the workpiece at both cylinder ends of the side pressure transmission cylinder. A plurality of pressure seal members arranged on at least one cylinder end, a metal member for holding each of the pressure seal members in a state of not contacting the workpiece, and the pressure seal member via the metal member At least one of the plurality of arranged side pressure seal members , and a pressure vessel for housing the side pressure transmission cylinder, the pressure seal member, the metal member, and the pressure means. One is arranged to seal the pressure to be released in the axial direction of the bar-shaped workpiece, and at least one of the other pressure seal members is a pressure to be released in the radial direction of the bar-shaped workpiece. The Place To Lumpur, wherein in a state in which the pressure sealing member is deformed under pressure by the pressurizing means, by loading the lateral pressure to the striations of the workpiece, the workpiece lateral pressure cutting apparatus for stress cut .

The side pressure cutting device according to claim 1, wherein the side pressure transmission cylinder is formed of a material having a Young's modulus smaller than that of the workpiece .

The side pressure cutting device according to claim 1 or 2, wherein a side pressure cutting device provided with a bar-shaped metal member disposed at least at one end of the bar-shaped workpiece and having an outer diameter equivalent to that of the bar-shaped workpiece. .

4. The side pressure cutting device according to claim 3, wherein the bar-shaped metal member is disposed so as to be fitted to the side pressure transmission cylinder at least during a side pressure load in the cutting process .