JP3927484B2

JP3927484B2 - Curved surface processing method and curved surface processing apparatus

Info

Publication number: JP3927484B2
Application number: JP2002343989A
Authority: JP
Inventors: 英利寒河江; 弘之遠藤
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2002-11-27
Filing date: 2002-11-27
Publication date: 2007-06-06
Anticipated expiration: 2022-11-27
Also published as: JP2004174665A

Description

【０００１】
【発明の属する技術分野】
本発明は、曲面の加工方法及び加工装置に関し、例えばレーザビームプリンタのポリゴンスキャナ光学系に用いられる、走査用レンズ、その金型等の曲面を加工する方法及び装置に関し、非球面、自由曲面等の曲面を有する光学素子、その金型等の加工に応用が可能なものである。
【０００２】
【従来の技術】
数値制御加工装置を用いて自由曲面を加工するためには、被加工面上にワーク座標系を展開することが必要で、ワーク座標の基準点となる加工原点が初めに被加工面上に設定される。この加工原点は被加工物の外周を構成する端面の交点であったり、対向する端面の中央にとられたりする。
【０００３】
光学素子用途の曲面においては、超精密切削や超精密研削等で所望の曲面の輪郭を形成する１次加工工程と、超精密研削や超精密研磨によって形状精度や表面粗さを仕上げる２次加工工程とが行われている。
【０００４】
１次加工における加工原点は、一般に被加工部材の側面や端面を基準に設定される。例えば図１１において、被加工物２１の平面で構成された側面２１ｂからの距離Ｊ，Ｍによって加工原点Ｐが設定される。ここで加工原点Ｐの設定とは、加工原点Ｐに立てたＺ軸に平行な直線と工具との曲率中心が一致する工作機械上のＸＹ座標値を求めることに相当する。
【０００５】
２次加工においては、１次加工と同様に加工原点の設定をして加工が行われる。２次加工が１次加工とは異なる工具又は加工機で実施されるので、再度の原点設定が必要となる。しかし、１次加工において実際に形成される曲面は、工具輪郭や加工機の位置決め誤差によって理想とした加工原点からずれて形成されるため、何らかの許容幅（＝公差）が与えられている。
【０００６】
２次加工が超精密研削で仕上げを行う工程とすると、２次加工で設定した加工原点が理想値（図１１に示す距離Ｊ，Ｍ）に対してズレのない加工ができたとしても１次加工の原点がずれていれば、原点ズレ自体も形状誤差の増大として作用するため、２次加工での取りしろが増えることとなる。２次加工では被加工面の除去単位が数十ｎｍ〜数μｍであり、加工能率は１次加工に比べ大幅に低いため、取りしろの増加は、納期やコスト面が極めて大きなロスとして作用する。このため取りしろをできる限り小さくすることが望まれている。
【０００７】
２次加工が前加工面を基準とした研磨工程の場合でも、うねりの山部のみを選択除去する修正研磨において、加工点の位置ズレによってうねりの山部が充分除去できず、精度不十分となる問題がある。特に加工面の形状評価は、加工物側面との位置関係とは無関係に、取得した形状データに対し数値計算で非球面軸等の加工中心を求め、求めた値を実際の加工原点として形状誤差の評価が行われる。このため前形状の修正研磨においては、形状評価で用いた加工原点を基準に修正加工を行うことが望ましい。
【０００８】
１次加工面の形状を加工機上で取得するものとして、特開平６−２８５７６２号公報の実施例に示されるように、タッチセンサ型のプローブを工具把持部につけかえ、加工機あるいは加工用ロボットの動作によって形状を取得する方法が従来より用いられている。
【０００９】
この方法の場合には、タッチセンサ型のプローブと２次加工用工具とを交換した際に工具把持位置の再現性が問題となり、工具を把持後に何らかの手段で実際の工具位置を評価しないと、結果として２次加工の加工原点がずれてしまう問題が残されている。
【００１０】
また、２次加工用の工具の位置を正確に取得する方法としては、例えば特開平７−１３６９０３号公報のように一度ダミーワークの加工を行い、得られた加工面の形状データを詳細に分析することで、工具の位置決め誤差、輪郭誤差を算出する手法が開示されている。この方法ではダミーワークを１度加工し計測するという作業が新たな工程として発生すること、加工中の工具磨耗の大小が演算結果を左右する等の問題が残されている。
【００１１】
また、従来、図１０に示すような曲面加工装置が知られている。この曲面加工装置は、研磨工具１０１（切削工具や研削工具でも可）によってダミー加工物１５４に対し加工痕を形成し、研磨ヘッド１１０と相対位置が変化せぬように連結部材１５２で連結された計測ヘッド１１１から形状測定用プローブ１５１で加工痕位置を計測し工具位置座標を取得する。続いて実際の被加工物を把持し形状測定用プローブ１５１により加工面形状データを取得し、頂点あるいは端面等の加工原点を検出し加工を行うものである。
【００１２】
【特許文献１】
特開平６−２８５７６２号公報（第３−５頁、図１〜１３）
【特許文献２】
特開平７−１３６９０３号公報
【００１３】
【発明が解決しようとする課題】
しかしながら、図１０に示す曲面加工装置の場合でも、特開平６−２８５７６２号公報に示されるものと同様に、研磨工具と計測ヘッドとの入れ替えに際して連結部材の機械的精度等により位置ずれによる加工原点ずれが発生し、充分な精度が得られないという問題があった。
【００１４】
また、図１０に示す曲面加工装置の場合においても、特開平７−１３６９０３号公報に示されるものと同様に、２次加工の前に、加工機の持つ座標系に対する被加工面の位置関係を取得するための加工が必要であった。
また、図１０に示す曲面加工装置の場合には、研磨ヘッドと計測ヘッドとの共存による装置の大型化という問題もあった。
【００１５】
そこで、本発明は、研磨工具と計測ヘッドとのずれによる加工原点ずれが無く、且つ２次加工の前に、加工機の持つ座標系に対する被加工面の位置関係を取得するための加工を行う必要がなく、装置の小型化も可能な曲面加工方法及び曲面加工装置を提供することをその目的とする。
【００１６】
【課題を解決するための手段】
上記目的を達成するために請求項１に記載の発明は、被加工物の被加工面を加工機で加工する曲面加工方法において、
前記被加工面に円弧断面を有する回転式加工工具の回転を停止してブレーキをかけた状態にて一定荷重で押しつけるとともに走査して、前記回転式加工工具を前記被加工面に沿った倣い動作をさせることにより、この回転式加工工具の加圧方向の変位を位置センサによって取得し、次に、この取得した加圧方向の変位から前記加工機の持つ座標系に対する被加工面の位置関係を取得し、そして、この取得した位置関係に基づいて前記被加工面を前記回転式加工工具で加工することを特徴とする曲面加工方法である。
【００１７】
また、請求項２に記載の発明は、被加工物の被加工面を加工機で加工する曲面加工方法において、
前記被加工面に円弧断面を有する回転式研磨工具の回転を停止してブレーキをかけた状態にて一定荷重で押しつけるとともに走査して、前記回転式研磨工具を前記被加工面に沿った倣い動作をさせることにより、この前記回転式研磨工具の加圧方向の変位を位置センサによって取得し、次に、この取得した加圧方向の変位から前記加工機の持つ座標系に対する前記被加工面の位置関係を取得する第１の工程と、この値に基づき前記被加工面上に加工原点を定め、前記被加工面に対して点接触となる前記回転式研磨工具を滞留時間制御で走査し形状を修正する第２の工程とを含むことを特徴とする曲面加工方法である。
【００１８】
また、請求項３に記載の発明は、請求項２に記載の曲面加工方法において、前記被加工面の座標を取得するためには、直動軸であるＸＹの直交２軸の制御で走査を行い、滞留時間制御による研磨加工時には、加工点の法線と加圧軸とを一致させるように傾き姿勢の制御をさらに行うことを特徴とする曲面加工方法である。
【００１９】
また、請求項４に記載の発明は、被加工物の被加工面を加工機で加工する曲面加工方法において、
前記被加工面に円弧断面を有する回転式研削工具の回転を停止してブレーキをかけた状態にて一定荷重で押しつけるとともに走査して、前記回転式研削工具を前記被加工面に沿った倣い動作をさせることにより、この前記回転式研削工具の加圧方向の変位を位置センサによって取得し、次に、この取得した加圧方向の変位から前記加工機の持つ座標系に対する被加工面の位置関係を取得する第１の工程と、この値に基づき前記被加工面上に加工原点を定め、その後、前記回転式研削工具の加圧軸としての可動ブロックを、加圧方向へ移動させるエアスライド本体に対して固定し、前記回転式研削工具の加圧方向の移動を固定した前記エアスライド本体に所望の工具軌跡を与えることで曲面形状を創成加工する第２の工程とを含むことを特徴とする曲面加工方法である。
【００２０】
また、請求項５に記載の発明は、請求項１〜４の何れかに記載の曲面加工方法において、前記被加工面の位置を取得するための前記工具の走査は、前記被加工面の曲面の頂点または最深部の近傍でＸとＹの２方向について走査し、２つの取得データの上死点または下死点から頂点または最深部の位置を決定することを特徴とする曲面加工方法である。
【００２１】
また、請求項６に記載の発明は、請求項５に記載の曲面加工方法において、前記頂点または最深部の位置の決定は、取得データに関数フィッティングによる近似曲線を求めることにより行うことを特徴とする曲面加工方法である。
【００２２】
また、請求項７に記載の発明は、請求項１〜４の何れかに記載の曲面加工方法において、前記被加工面の位置を取得するための前記工具の走査は、前記工具が前記被加工面から外れて落下する位置まで走査を行い、その落下開始点の工具座標から、前記被加工面のエッジあるいは型部材の側面の位置を決定することを特徴とする曲面加工方法である。
【００２３】
また、請求項８に記載の発明は、被加工物の被加工面を加工機で加工する曲面加工装置において、
円弧断面を有する回転式加工工具と、該回転式加工工具の回転を停止してブレーキをかけた状態にて前記被加工面に一定荷重で押しつける加圧機構と、前記回転式加工工具が載置され加圧方向に移動可能な可動ブロックと、該可動ブロックの位置を検出する位置センサと、前記回転式加工工具を前記被加工面に一定荷重で走査して倣い動作させ、前記位置センサの出力に基づき、前記加工機の持つ座標系に対する前記被加工面の位置関係を取得する手段と、
取得した位置関係に基づいて前記被加工面を前記回転式加工工具で加工する手段とを備えていることを特徴とする曲面加工装置である。
【００２４】
また、請求項９に記載の発明は、被加工物の被加工面を加工機で加工する曲面加工装置において、
円弧断面を有する回転式加工工具と、該回転式加工工具の先端の回転を停止してブレーキをかけた状態にて前記被加工面に一定荷重で押しつける加圧機構と、前記回転式加工工具が載置され加圧方向に移動可能な可動ブロックと、該可動ブロックの位置を検出する位置センサと、前記可動ブロックを、加圧方向へ移動させるエアスライド本体に対して特定の位置に固定する固定手段と、前記回転式加工工具に切り込み量を与える位置決め制御機構と、前記回転式加工工具を前記被加工面に一定荷重で走査して倣い動作させ、前記位置センサの出力に基づき、前記加工機の持つ座標系に対する前記被加工面の位置関係を取得する手段と、その後可動ブロックが固定されたエアスライド本体に所望の軌跡を発生させ、被加工面へ工具軌跡を転写する手段とを備えていることを特徴とする曲面加工装置である。
【００２５】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して説明する。
図１は本発明に係る一実施形態の曲面加工装置に備える研磨ヘッドを示す概略斜視図である。図１では研磨工具を形状測定用プローブとして用いるための研磨ヘッド部の構成を示している。
【００２６】
図１に示すように、この研磨ヘッド部は、工具スピンドル２によって回転駆動される研磨工具１と、エアスライドレール４の上を移動する可動ブロック３に連結されている工具スピンドル２と、エアスライドレール４が取り付けられたエアスライド本体５の側面に取りつけられたレーザースケール本体６と、可動ブロック３に取り付けられたレーザースケール検出ヘッド７とを備えて構成されている。
【００２７】
前記可動ブロック４の位置はエアスライド本体５の側面に取りつけられたレーザースケール本体６とレーザースケール検出ヘッド７とにより０．０５μｍの分解能で検出可能となっている。
【００２８】
図２は図１の研磨ヘッドを組み込んだ、本発明に係る一実施形態の曲面加工装置を示す概略正面図である。
図２に示すように、可動ブロック３はロードセル９を介してエアシリンダ８に連結され、研磨工具１はこのエアシリンダ８の推力によって、被加工物２１に押しつけ力を発生させる。研磨工具１の押しつけ力はロードセル９によってモニターされ、モニターされた押しつけ力が所望の荷重となるよう荷重制御を行っている。エアシリンダ８は工具スピンドル２を含めた可動ブロック３の自重補償もかねており、研磨工具１の押しつけ力としては５ｇまでが設定可能である。被加工物２１は図示しないＸＹ軸移動機構により直線運動で走査される。研磨工具１は曲面に沿って上下動をし、このＺ方向変位をＸＹ座標と同期した形態で取得するものである。相対的には被加工面２１ａを有する被加工物２１に対してエアスライド本体５を走査したことになる。なお、図２中、符号２２はワークテーブル、２３はＺ軸コラムをそれぞれ示す。
以下ではエアスライド本体５の走査として説明をすすめる。
【００２９】
図３は本発明に係る一実施形態の曲面加工装置による、加工機の持つ座標系に対する被加工面の位置関係を取得する動作を示す図である。図３では研磨工具を形状測定プローブに見立て形状データの取得動作を示すものである。
【００３０】
図３にも示す研磨工具１は木粉をウレタン樹脂て固めたものである。被加工物２１は近軸曲率が凸形状である非球面で材質は無電解Ｎｉ−Ｐメッキでダイヤモンド切削で仕上げられた面である。砥粒を付与する前の研磨工具１を停止状態にて非球面の頂点近傍で接触させ、Ｘ軸方向へエアスライド本体５を直線運動で移動させ、その時の研磨工具１のＺ変位をレーザースケール検出ヘッド７で検出を行う。
【００３１】
図４は図３の曲面加工装置における、加工原点設定後の研磨動作を示す図である。
図４に示すように、図３の形状計測の状態と異なるのは、被加工面２１ａにダイヤモンドペーストを塗布し、研磨工具１に回転を当て得ていることである。より高精度なものに対しては、加工点法線と荷重軸とが一致するような法線姿勢制御を付与することが必要である。
【００３２】
図５は本発明に係る他の実施形態の曲面加工装置による、加工機の持つ座標系に対する被加工面の位置関係を取得する動作を示す図、図６は図５の曲面加工装置における、加工原点設定後の研削動作を示す図である。
【００３３】
図５では、形状データの取得後にツールパスを転写する様な研削加工を可能とするものである。研削工具としては研磨工具１と同一の形状を有する軸付きのレジン砥石６１を用いている。本実施形態と図１〜図４で説明した実施形態との違いは可動ブロック３を固定するためのクランプ機構３１を持つ点であり、他の構成は同様である。
【００３４】
図５に示すように、形状データの取得状態でクランプ機構３１は解放されており、図６に示すように、クランプ機構３１のクランプにより可動ブロック３が固定されたクランプ状態となり、定寸切り込みが可能な形態となっている。この状態でエアスライド本体５を図示しない移動機構を用いて所定のツールパスで移動させることにより、軌跡転写としての曲面の研削加工が可能となっている。
【００３５】
図７は本発明に係る曲面加工装置を用いて、従来の加工基準である端面位置の検出が可能であることを示す図である。
図７に示すように、荷重制御状態で研磨工具１が落下点Ｐ１を検出し、落下点Ｐ１から工具曲率半径だけオフセットすることで被加工物２１の端面座標を求めることが可能である。
【００３６】
図８は本発明の曲面加工装置により、被加工物の凹面の最深点の検出を示す図である。
図８は凹面の最深点を求めるものである。下死点Ｐ２から加工原点を求めている。凹面に比べ凸面の場合同じ曲率半径であってもＸ軸の走査移動量に対するＺの変化が緩やかとなるため、上死点のＸ位置検出が困難となる場合がある。このような場合は走査移動量の増大や円弧または２次関数等の近似関数のフィッティングを併用することで、正確な頂点位置の特定が可能となる。
【００３７】
図９は第２の工程として法線姿勢制御を付与した曲面加工装置の一例としての研磨装置を示す図である。図９では研磨ヘッドは省略し研磨工具２１のみを記載する。
図９に示すように、この研磨装置は、Ｘ軸直動ステージ４８、Ｙ軸直動ステージ４９及び図示しないＺ軸コラムからなる、ＸＹＺの直交３軸の直動スライドと、Ｘ軸周りの回転姿勢を制御するＡ軸チルトステージ４６及びＹ軸周りの回転姿勢を制御するＢ軸チルトステージ４７からなる２軸のチルトステージとを備えて構成され、５軸のＮＣ（numerical control）位置決め制御を可能とするものである。
【００３８】
被加工物２１は、Ａ軸チルトステージ４６上に母線を長手の側面をＸ軸と平行に図示しないチャック機構によりチャックされている。研磨工具１の走査軌跡は、図９の研磨加工のツールパス４５に示すように、Ｙ方向に１ライン走査しＸ方向にピックフィードして再度Ｙ方向に走査する動作を繰り返し加工を行った。この際に研磨工具１の加圧方向であるＺ軸と加工点の法線とが常に一致するように、ＸＹＡＢの４軸同時制御を付与している。
【００３９】
上述した研磨加工は、研磨工具１を例えば滞留時間制御することにより行うことができ、また、上述した研削加工は、研削工具であるレジン砥石６１を例えば軌跡制御しこれを転写することにより行うことができる。滞留時間制御では、被加工面に研磨工具又は研削工具が当接している平均滞留時間を制御することにより、加工量を制御することができる。
【００４０】
以上の曲面を高精度に仕上げる研削および研磨において、円弧断面を有する球状またはトロイダル形状（＝タイヤ形状）の加工工具の使用を前提とする。この加工工具先端を触針式の形状測定プロ―ブにみたて、微弱でかつ一定の荷重で１次加工を経た被加工面に押しつけ走査する。加工工具は、回転を停止してブレーキをかけた状態とし、被加工面である曲面の頂点近傍で接触させる。走査には荷重方向であるＺ軸と直交するＸ軸（またはＹ軸）で行う。加工工具は被加工面に沿って倣い動作を行う、このときの工具のＺ軸方向変位をリニアスケールで取り込みＸＺの曲線として取得する。Ｙ軸方向にも同様の走査でＹＺの曲線をそれぞれの曲線の上死点または関数フィッティングで求まる原点から被加工面の頂点を工具によって取得し、これを加工原点とする。
【００４１】
１次加工面の形状を取得し、その形状データから実際に形成されている加工原点の位置を求め、これを基準にし、さらには２次加工の加工原点を正確にこれに一致させることができる。
【００４２】
上記の１次加工において得られた加工面形状から、実際に形成された加工原点を割り出し、これを基準として、２次加工を行う事で２次加工の取りしろを極力小さくし、無駄のない高精度で高能率な曲面加工を実現する、加工法ならびに加工装置を提供することができる。
【００４３】
２次加工が研削工程の場合倣い動作を行った荷重制御軸の直動スライドをクランプし定寸での切り込み動作が可能な状態に装置形態を変更し曲面形状の創成加工を行う。
【００４４】
２次加工が研磨工程の場合は装置形態は上記クランプは不要となる。但し高精度加工時には荷重軸と加工点の法線が工具走査に伴いつねに一致するような法線姿勢制御を用いた研磨動作となる。
【００４５】
上述した曲面加工法又は曲面加工装置により光学素子、光学素子成形型（金型）又はその成形品を作製することにより、曲面の光学素子あるいはその金型が従来なしえなかった精度と加工時間で製作可能となり結果として、これらを組み込んだ光学系や画像形成機器の性能向上と低コスト化が実現される。
なお、本発明は上記実施例に限定されるものではない。即ち、本発明の骨子を逸脱しない範囲で種々変形して実施することができる。
【００４６】
【発明の効果】
以上説明したように、請求項１の発明によれば、小型な装置構成でかつダミー加工物の予備加工といった手間を経ることもなく、１次加工面基準の加工を正確に行うことができ、高効率で高精度な曲面の仕上加工を実現することができる。
【００４７】
請求項２又は請求項８の発明によれば、小型な装置構成でかつダミー加工物の予備加工といった手間を経ることもなく、点接触の研磨工具を走査する仕上げ加工が正確な１次加工面基準のもとに実施可能となり、高効率で高精度な曲面の仕上加工が実現される。また、安価な高精度加工機の提供が可能となる。
【００４８】
請求項４又は請求項９の発明によれば、小型な装置構成でかつダミー加工物の予備加工といった手間を経ることもなく、軌跡転写型の曲面の研削仕上げ加工が正確な１次加工面基準のもとに実施可能となり、高効率で高精度な曲面の仕上加工が実現される。安価な高精度加工機の提供が可能となる。
【００４９】
請求項３の発明によれば、正確な１次加工面基準の加工法と法線姿勢制御を付与した点接触研磨加工の組み合わせによって、曲面の光学素子あるいはその金型が従来なしえなかった精度とリードタイムで製作可能となる。
【００５０】
請求項５の発明によれば、上死点あるいは下死点といった直接的な指標で加工原点を得ることで、段取り時間が極めて短縮できる。
【００５１】
請求項７の発明によれば、頂点のみならず立ち壁となる端面やエッジの位置も同様に簡易で短時間で検出可能となる。
【００５２】
請求項６の発明によれば、曲率半径が大きく頂点探索が困難な形状においても、関数フィッティングの手法を組み合わせることで正確な頂点位置の取得が可能となる。演算自体も非常にシンプルであるため、段取り時間のロスはほとんど与えずに使用可能である。
【図面の簡単な説明】
【図１】本発明に係る一実施形態の曲面加工装置に備える研磨ヘッドを示す概略斜視図である。
【図２】図１の研磨ヘッドを組み込んだ、本発明に係る一実施形態の曲面加工装置を示す概略正面図である。
【図３】本発明に係る一実施形態の曲面加工装置による、加工機の持つ座標系に対する被加工面の位置関係を取得する動作を示す図である。
【図４】図３の曲面加工装置における、加工原点設定後の研磨動作を示す図である。
【図５】本発明に係る他の実施形態の曲面加工装置による、加工機の持つ座標系に対する被加工面の位置関係を取得する動作を示す図である。
【図６】図５の曲面加工装置における、加工原点設定後の研削動作を示す図である。
【図７】本発明に係る曲面加工装置を用いて、従来の加工基準である端面位置の検出が可能であることを示す図である。
【図８】本発明の曲面加工装置により、被加工物の最深点の検出を示す図である。
【図９】第２の工程として法線姿勢制御を付与した曲面加工装置の一例としての研磨装置を示す図である。
【図１０】従来の曲面加工装置の要部を示す概略図である。
【図１１】１次加工原点の設定方法を示す図である。
【符号の説明】
１研磨工具（加工工具）
２工具スピンドル
３可動ブロック
４エアスライドレール
５エアスライド本体
６レーザスケール本体（位置センサ）
７レーザスケール検出ヘッド（位置センサ）
８エアシリンダ
９ロードセル
２１被加工物
２１ａ被加工面
３１クランプ機構
４５研磨加工のツールパス
４６Ａ軸チルトステージ
４７Ｂ軸チルトステージ
４８Ｘ軸直動ステージ
４９Ｙ軸直動ステージ
６１レジン砥石（加工工具）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a curved surface processing method and processing apparatus, for example, a scanning lens used in a polygon scanner optical system of a laser beam printer, a method and apparatus for processing a curved surface of a mold thereof, an aspherical surface, a free curved surface, and the like. The present invention can be applied to the processing of optical elements having a curved surface and molds thereof.
[0002]
[Prior art]
In order to machine a free-form surface using a numerically controlled machining device, it is necessary to develop a workpiece coordinate system on the workpiece surface, and the machining origin serving as the workpiece coordinate reference point is first set on the workpiece surface. Is done. This processing origin is the intersection of the end surfaces constituting the outer periphery of the workpiece, or is taken at the center of the opposing end surfaces.
[0003]
For curved surfaces for optical elements, the primary machining process that forms the contour of the desired curved surface by ultra-precision cutting or ultra-precision grinding, and the secondary machining that finishes the shape accuracy or surface roughness by ultra-precision grinding or ultra-precision polishing. Process.
[0004]
The processing origin in primary processing is generally set on the basis of the side surface and end surface of the workpiece. For example, in FIG. 11, the processing origin P is set by the distances J and M from the side surface 21 b configured by the plane of the workpiece 21. Here, the setting of the machining origin P corresponds to obtaining an XY coordinate value on the machine tool where the straight line parallel to the Z axis set at the machining origin P and the center of curvature of the tool coincide.
[0005]
In the secondary machining, the machining origin is set and machining is performed as in the primary machining. Since the secondary processing is performed by a tool or a processing machine different from the primary processing, it is necessary to set the origin again. However, since the curved surface actually formed in the primary machining is formed with a deviation from the ideal machining origin due to the tool contour or the positioning error of the machine, some tolerance (= tolerance) is given.
[0006]
If the secondary machining is a process of finishing by ultra-precision grinding, even if the machining origin set in the secondary machining can be machined without deviation from the ideal values (distances J and M shown in FIG. 11), the primary machining is performed. If the machining origin is deviated, the origin deviation itself acts as an increase in the shape error, so that the margin for secondary machining increases. In secondary machining, the removal unit of the work surface is several tens of nanometers to several μm, and the machining efficiency is significantly lower than that of the primary machining. Therefore, the increase in margins acts as an extremely large loss in terms of delivery time and cost. . For this reason, it is desired to make the margin as small as possible.
[0007]
Even in the case where the secondary process is a polishing process based on the pre-processed surface, in the correction polishing in which only the waviness peak is selectively removed, the waviness crest cannot be sufficiently removed due to the displacement of the processing point, and the accuracy is insufficient. There is a problem. In particular, when evaluating the shape of the machined surface, regardless of the positional relationship with the workpiece side surface, the machining center such as the aspherical axis is obtained by numerical calculation of the obtained shape data, and the obtained value is used as the actual machining origin to obtain a shape error. Is evaluated. For this reason, in the correction polishing of the previous shape, it is desirable to perform correction processing based on the processing origin used in the shape evaluation.
[0008]
In order to acquire the shape of the primary processing surface on the processing machine, as shown in the example of Japanese Patent Laid-Open No. 6-285762, a touch sensor type probe is replaced with a tool gripping part, and the processing machine or processing robot Conventionally, a method for obtaining a shape by the above operation has been used.
[0009]
In the case of this method, when the touch sensor type probe and the secondary processing tool are exchanged, the reproducibility of the tool grip position becomes a problem, and if the actual tool position is not evaluated by any means after gripping the tool, As a result, there remains a problem that the machining origin of the secondary machining is shifted.
[0010]
Also, as a method for accurately obtaining the position of the tool for secondary machining, for example, as disclosed in JP-A-7-136903, a dummy workpiece is machined once, and the shape data of the obtained machining surface is analyzed in detail. Thus, a technique for calculating a tool positioning error and a contour error is disclosed. In this method, the work of machining and measuring the dummy workpiece once occurs as a new process, and the problem that the magnitude of tool wear during machining affects the calculation result remains.
[0011]
Conventionally, a curved surface processing apparatus as shown in FIG. 10 is known. This curved surface processing apparatus forms a processing mark on the dummy workpiece 154 with the polishing tool 101 (which may be a cutting tool or a grinding tool), and is connected to the polishing head 110 by a connecting member 152 so that the relative position does not change. The machining mark position is measured from the measuring head 111 with the shape measuring probe 151 to acquire the tool position coordinates. Subsequently, the actual workpiece is gripped, the machining surface shape data is acquired by the shape measuring probe 151, and the machining origin such as the apex or the end surface is detected to perform the machining.
[0012]
[Patent Document 1]
JP-A-6-285762 (page 3-5, FIGS. 1 to 13)
[Patent Document 2]
JP-A-7-136903 [0013]
[Problems to be solved by the invention]
However, even in the case of the curved surface processing apparatus shown in FIG. 10, as in the case of Japanese Patent Laid-Open No. 6-285762, the origin of processing due to misalignment due to the mechanical accuracy of the connecting member when the polishing tool and the measuring head are replaced. There was a problem that a deviation occurred and sufficient accuracy could not be obtained.
[0014]
Also in the case of the curved surface processing apparatus shown in FIG. 10, the positional relationship of the surface to be processed with respect to the coordinate system of the processing machine is determined prior to the secondary processing, as in the case of Japanese Patent Laid-Open No. 7-136903. Processing to acquire was necessary.
Further, in the case of the curved surface processing apparatus shown in FIG. 10, there is a problem that the apparatus becomes large due to the coexistence of the polishing head and the measurement head.
[0015]
Therefore, the present invention performs processing for obtaining the positional relationship of the surface to be processed with respect to the coordinate system of the processing machine before the secondary processing, without causing a processing origin deviation due to a deviation between the polishing tool and the measuring head. It is an object of the present invention to provide a curved surface processing method and a curved surface processing apparatus that are not necessary and can be downsized.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a curved surface machining method for machining a workpiece surface of a workpiece with a processing machine.
The scanning with pressing at a constant load in a state where the rotation of the rotary machining tool braked to stop having an arc cross-section to be processed surface, following the rotary machining tool along the workpiece surface operation the Rukoto allowed to acquire the displacement of the pressing direction of this rotary machining tool by the position sensor, then the surface to be processed with respect to the coordinate system having from the acquired pressure direction of displacement of the machine get the positional relationship, and a curved surface machining method characterized by processing by the rotary machining tool to the workpiece surface based on the obtained position relationship.
[0017]
Further, the invention according to claim 2 is a curved surface processing method for processing a processing surface of a workpiece with a processing machine.
The rotary polishing tool having an arc cross section on the work surface is stopped and pressed with a constant load in a braked state and scanned, and the rotary polishing tool is scanned along the work surface. the Rukoto allowed to acquire the displacement of the pressure direction before Symbol rotary polishing tool this by the position sensor, then the object to be processed with respect to the coordinate system having from the acquired pressure direction of displacement of the machine A first step of acquiring the positional relationship of the surface, and a processing origin is determined on the processing surface based on this value, and the rotary polishing tool that is in point contact with the processing surface is scanned by dwell time control. And a second step of correcting the shape of the curved surface.
[0018]
According to a third aspect of the present invention, in the curved surface processing method according to the second aspect, in order to obtain the coordinates of the surface to be processed, scanning is performed by controlling two orthogonal axes of XY that are linear motion axes. The curved surface machining method is characterized in that the tilting posture is further controlled so that the normal of the machining point and the pressure axis coincide with each other at the time of polishing by dwell time control.
[0019]
Further, the invention according to claim 4 is a curved surface machining method of machining a work surface of a work piece with a processing machine.
The rotary grinding tool having an arc cross section on the work surface is stopped and pressed with a constant load in a braked state and scanned, and the rotary grinding tool is scanned along the work surface. the Rukoto allowed to acquire the displacement of the pressure direction before Symbol rotary grinding tool of this by the position sensor, then the processed surface with respect to the coordinate system having from the acquired pressure direction of displacement of the machine The first step of acquiring the positional relationship and the processing origin is determined on the processing surface based on this value, and then the movable block as the pressing shaft of the rotary grinding tool is moved in the pressing direction. A second step of creating a curved surface shape by giving a desired tool locus to the air slide body fixed to the air slide body and fixed in the pressure direction of the rotary grinding tool. With features Is that curved surface processing method.
[0020]
The invention according to claim 5 is the curved surface machining method according to any one of claims 1 to 4, wherein the scanning of the tool for obtaining the position of the work surface is a curved surface of the work surface. The curved surface processing method is characterized by scanning in two directions of X and Y in the vicinity of the vertex or deepest part of the image and determining the position of the vertex or deepest part from the top dead center or bottom dead center of the two acquired data .
[0021]
The invention according to claim 6 is the curved surface processing method according to claim 5, wherein the position of the vertex or the deepest portion is determined by obtaining an approximate curve by function fitting to the acquired data. This is a curved surface processing method.
[0022]
The invention according to claim 7 is the curved surface machining method according to any one of claims 1 to 4, wherein the tool scans the workpiece to obtain the position of the workpiece surface. It is a curved surface machining method characterized by scanning to a position where it falls off the surface and determining the position of the edge of the work surface or the side surface of the mold member from the tool coordinates of the drop start point.
[0023]
The invention according to claim 8 is a curved surface processing apparatus for processing a processing surface of a workpiece with a processing machine.
A rotary machining tool, a pressure mechanism for pressing at a constant load to the surface to be processed in a state in which braking to stop the rotation of the rotary machining tool, the rotary machining tool is placed with an arc cross-section A movable block that is movable in the pressurizing direction, a position sensor that detects the position of the movable block, and a scanning operation of the rotary processing tool on the surface to be processed with a constant load, and an output of the position sensor And means for acquiring a positional relationship of the processing surface with respect to a coordinate system of the processing machine,
A curved surface machining apparatus comprising: means for machining the work surface with the rotary machining tool based on the acquired positional relationship.
[0024]
The invention according to claim 9 is a curved surface processing apparatus for processing a processing surface of a workpiece with a processing machine.
A rotary machining tool having an arcuate cross-section, a pressure mechanism for pressing at a constant load to the surface to be processed in a state in which braking to stop the rotation of the tip of the rotary machining tool, said rotary working tool A movable block that is mounted and movable in the pressurizing direction , a position sensor that detects the position of the movable block , and a fixing that fixes the movable block at a specific position with respect to the air slide body that moves in the pressurizing direction. means, a positioning control mechanism for giving a depth of cut in the rotary working tool, the rotary machining tool is scanned by the scanning operation at a constant load to the workpiece surface, based on an output of the position sensor, the machine be transferred and means for obtaining the positional relationship of the surface to be processed with respect to the coordinate system, thereby subsequently generating a desired trajectory to the air slide body movable block is fixed, the tool path to the work surface with the It is a curved surface machining apparatus according to claim that a unit.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view showing a polishing head provided in a curved surface processing apparatus according to an embodiment of the present invention. FIG. 1 shows a configuration of a polishing head unit for using a polishing tool as a shape measuring probe.
[0026]
As shown in FIG. 1, the polishing head section includes a polishing tool 1 that is rotationally driven by a tool spindle 2, a tool spindle 2 that is connected to a movable block 3 that moves on an air slide rail 4, and an air slide. A laser scale body 6 attached to the side surface of the air slide body 5 to which the rail 4 is attached, and a laser scale detection head 7 attached to the movable block 3 are configured.
[0027]
The position of the movable block 4 can be detected with a resolution of 0.05 μm by a laser scale body 6 and a laser scale detection head 7 mounted on the side surface of the air slide body 5.
[0028]
FIG. 2 is a schematic front view showing a curved surface processing apparatus according to an embodiment of the present invention in which the polishing head of FIG. 1 is incorporated.
As shown in FIG. 2, the movable block 3 is connected to the air cylinder 8 via the load cell 9, and the polishing tool 1 generates a pressing force against the workpiece 21 by the thrust of the air cylinder 8. The pressing force of the polishing tool 1 is monitored by the load cell 9, and load control is performed so that the monitored pressing force becomes a desired load. The air cylinder 8 also compensates for its own weight of the movable block 3 including the tool spindle 2, and the pressing force of the polishing tool 1 can be set up to 5 g. The workpiece 21 is scanned by a linear motion by an XY axis moving mechanism (not shown). The polishing tool 1 moves up and down along the curved surface, and acquires the displacement in the Z direction in a form synchronized with the XY coordinates. In comparison, the air slide body 5 is scanned with respect to the workpiece 21 having the workpiece surface 21a. In FIG. 2, reference numeral 22 denotes a work table, and 23 denotes a Z-axis column.
In the following, description will be given as scanning of the air slide body 5.
[0029]
FIG. 3 is a diagram illustrating an operation of acquiring the positional relationship of the surface to be processed with respect to the coordinate system of the processing machine by the curved surface processing apparatus according to the embodiment of the present invention. FIG. 3 shows an operation of acquiring shape data by using a polishing tool as a shape measuring probe.
[0030]
The polishing tool 1 shown also in FIG. 3 is made of wood powder hardened with urethane resin. The workpiece 21 is an aspherical surface having a convex paraxial curvature, and the material is a surface finished by electroless Ni-P plating and diamond cutting. The polishing tool 1 before applying abrasive grains is brought into contact with the vicinity of the top of the aspherical surface in a stopped state, and the air slide body 5 is moved in a linear motion in the X-axis direction, and the Z displacement of the polishing tool 1 at that time is laser scaled Detection is performed by the detection head 7.
[0031]
FIG. 4 is a diagram showing a polishing operation after setting the processing origin in the curved surface processing apparatus of FIG.
As shown in FIG. 4, the difference from the shape measurement state of FIG. 3 is that a diamond paste is applied to the work surface 21 a and the polishing tool 1 can be rotated. For higher accuracy, it is necessary to provide normal posture control so that the machining point normal matches the load axis.
[0032]
FIG. 5 is a diagram showing an operation of acquiring the positional relationship of the processing surface with respect to the coordinate system of the processing machine by the curved surface processing apparatus according to another embodiment of the present invention, and FIG. 6 is a processing in the curved surface processing apparatus of FIG. It is a figure which shows the grinding operation after an origin setting.
[0033]
In FIG. 5, grinding such as transferring a tool path after obtaining shape data is enabled. As the grinding tool, a resin grindstone 61 with a shaft having the same shape as the polishing tool 1 is used. The difference between the present embodiment and the embodiment described with reference to FIGS. 1 to 4 is that a clamp mechanism 31 for fixing the movable block 3 is provided, and other configurations are the same.
[0034]
As shown in FIG. 5, the clamp mechanism 31 is released in the state where the shape data is acquired, and as shown in FIG. 6, the movable block 3 is fixed by the clamp of the clamp mechanism 31, and the fixed-dimension cut is performed. It is a possible form. In this state, by moving the air slide body 5 with a predetermined tool path using a moving mechanism (not shown), it is possible to grind the curved surface as a locus transfer.
[0035]
FIG. 7 is a diagram showing that the end face position, which is a conventional machining reference, can be detected using the curved surface machining apparatus according to the present invention.
As shown in FIG. 7, the polishing tool 1 detects the drop point P1 in the load control state, and the end surface coordinates of the workpiece 21 can be obtained by offsetting the tool curvature radius from the drop point P1.
[0036]
FIG. 8 is a diagram showing detection of the deepest point of the concave surface of the workpiece by the curved surface processing apparatus of the present invention.
FIG. 8 shows the deepest point of the concave surface. The processing origin is obtained from the bottom dead center P2. In the case of a convex surface compared to a concave surface, even if the radius of curvature is the same, the change in Z with respect to the scanning movement amount of the X axis becomes gradual, and it may be difficult to detect the X position of the top dead center. In such a case, an accurate apex position can be specified by using an increase in scanning movement amount and fitting of an approximate function such as an arc or a quadratic function.
[0037]
FIG. 9 is a diagram showing a polishing apparatus as an example of a curved surface processing apparatus provided with normal posture control as the second step. In FIG. 9, the polishing head is omitted and only the polishing tool 21 is shown.
As shown in FIG. 9, this polishing apparatus includes an X-axis linear motion stage 48, a Y-axis linear motion stage 49, and a Z-axis column (not shown), and three XYZ orthogonal linear motion slides and rotation around the X-axis. A 2-axis tilt stage consisting of an A-axis tilt stage 46 for controlling the attitude and a B-axis tilt stage 47 for controlling the rotation attitude around the Y-axis, and 5-axis NC (numerical control) positioning control is possible. It is what.
[0038]
The workpiece 21 is chucked on the A-axis tilt stage 46 by a chuck mechanism (not shown) with the generatrix and the long side surface parallel to the X-axis. The scanning trajectory of the polishing tool 1 was repeatedly processed by scanning one line in the Y direction, pick-feeding in the X direction, and scanning in the Y direction again as shown in the polishing tool path 45 in FIG. At this time, four-axis simultaneous control of XYAB is given so that the Z-axis which is the pressing direction of the polishing tool 1 and the normal of the machining point always coincide.
[0039]
The above-described polishing process can be performed by, for example, controlling the dwell time of the polishing tool 1, and the above-described grinding process is performed by, for example, controlling the trajectory of the resin grindstone 61 that is a grinding tool and transferring it. Can do. In the residence time control, the amount of machining can be controlled by controlling the average residence time in which the polishing tool or the grinding tool is in contact with the work surface.
[0040]
In grinding and polishing for finishing the above curved surface with high accuracy, it is assumed that a spherical or toroidal (= tire shape) processing tool having an arc cross section is used. The tip of the processing tool is seen by a stylus-type shape measurement probe, and is scanned by pressing it against the work surface that has undergone primary processing with a weak and constant load. The machining tool is brought into a state where the rotation is stopped and the brake is applied, and the machining tool is brought into contact in the vicinity of the vertex of the curved surface which is the machining surface. Scanning is performed on the X axis (or Y axis) orthogonal to the Z axis, which is the load direction. The machining tool performs a copying operation along the surface to be machined. The Z-axis direction displacement of the tool at this time is taken in with a linear scale and is acquired as an XZ curve. In the Y-axis direction as well, YZ curves are obtained by the same scanning, and the vertices of the surface to be machined are obtained by the tool from the top dead center of each curve or the origin obtained by function fitting, and this is used as the machining origin.
[0041]
The shape of the primary machining surface is acquired, the position of the machining origin actually formed is obtained from the shape data, this can be used as a reference, and the machining origin of the secondary machining can be accurately matched to this. .
[0042]
The machining origin actually formed is determined from the machining surface shape obtained in the above-mentioned primary machining, and the secondary machining is performed based on this to make the margin for the secondary machining as small as possible, and there is no waste. It is possible to provide a processing method and a processing apparatus that realize highly accurate and highly efficient curved surface processing.
[0043]
When the secondary process is a grinding process, the linear motion slide of the load control shaft that performed the copying operation is clamped, and the apparatus configuration is changed to a state where a cutting operation with a constant dimension is possible, and a curved surface shape creation process is performed.
[0044]
When the secondary process is a polishing process, the above-described clamp is not required for the apparatus configuration. However, at the time of high-precision machining, the polishing operation uses the normal posture control so that the normal line of the load axis and the machining point always coincide with the tool scanning.
[0045]
By producing an optical element, an optical element molding die (mold) or a molded product thereof by the curved surface processing method or curved surface processing apparatus described above, the curved optical element or its mold can be achieved with accuracy and processing time that could not be achieved conventionally. As a result, it is possible to improve the performance and reduce the cost of optical systems and image forming apparatuses incorporating these.
In addition, this invention is not limited to the said Example. That is, various modifications can be made without departing from the scope of the present invention.
[0046]
【The invention's effect】
As described above, according to the invention of claim 1, it is possible to accurately perform the processing on the basis of the primary processing surface without a trouble of preliminary processing of the dummy workpiece with a small device configuration, Highly efficient and highly accurate curved surface finishing can be realized.
[0047]
According to the second or eighth aspect of the invention, the primary processing surface has a small device configuration and does not require the time for preliminary processing of the dummy workpiece, and the finishing processing for scanning the point contact polishing tool is accurate. It becomes possible to carry out based on the standard, and high-efficiency and high-precision finishing of curved surfaces is realized. In addition, it is possible to provide an inexpensive high-precision processing machine.
[0048]
According to the fourth or ninth aspect of the present invention, the primary machined surface reference is accurate in the grinding process of the curved surface of the trajectory transfer type with a small apparatus configuration and without the trouble of preliminary machining of the dummy workpiece. Therefore, it is possible to carry out highly efficient and highly accurate curved surface finishing. It is possible to provide an inexpensive high-precision processing machine.
[0049]
According to the invention of claim 3, the accuracy of the curved optical element or its mold cannot be achieved conventionally by the combination of the processing method based on the accurate primary processing surface and the point contact polishing processing with the normal posture control. It becomes possible to produce with lead time.
[0050]
According to the invention of claim 5, the set-up time can be greatly shortened by obtaining the processing origin with a direct index such as top dead center or bottom dead center.
[0051]
According to the seventh aspect of the invention, not only the apex but also the position of the end face or edge that becomes the standing wall can be detected in a simple and short time.
[0052]
According to the sixth aspect of the present invention, even when the curvature radius is large and the vertex search is difficult, the vertex position can be accurately obtained by combining the function fitting methods. Since the calculation itself is very simple, it can be used with little loss of setup time.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a polishing head provided in a curved surface processing apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic front view showing a curved surface processing apparatus according to an embodiment of the present invention, in which the polishing head of FIG. 1 is incorporated.
FIG. 3 is a diagram illustrating an operation of acquiring a positional relationship of a processing surface with respect to a coordinate system of a processing machine by a curved surface processing apparatus according to an embodiment of the present invention.
4 is a diagram showing a polishing operation after setting a processing origin in the curved surface processing apparatus of FIG. 3; FIG.
FIG. 5 is a diagram illustrating an operation of acquiring a positional relationship of a surface to be processed with respect to a coordinate system of a processing machine by a curved surface processing apparatus according to another embodiment of the present invention.
6 is a diagram showing a grinding operation after setting a processing origin in the curved surface processing apparatus of FIG. 5; FIG.
FIG. 7 is a diagram showing that the end face position, which is a conventional machining reference, can be detected using the curved surface machining apparatus according to the present invention.
FIG. 8 is a diagram showing detection of the deepest point of the workpiece by the curved surface processing apparatus of the present invention.
FIG. 9 is a diagram showing a polishing apparatus as an example of a curved surface processing apparatus provided with normal posture control as a second step.
FIG. 10 is a schematic view showing a main part of a conventional curved surface processing apparatus.
FIG. 11 is a diagram illustrating a method for setting a primary machining origin.
[Explanation of symbols]
1 Polishing tool (processing tool)
2 Tool spindle 3 Movable block 4 Air slide rail 5 Air slide body 6 Laser scale body (position sensor)
7 Laser scale detection head (position sensor)
8 Air cylinder 9 Load cell 21 Work piece 21a Work surface 31 Clamp mechanism 45 Polishing tool path 46 A-axis tilt stage 47 B-axis tilt stage 48 X-axis linear motion stage 49 Y-axis linear motion stage 61 Resin grindstone (processing tool )

Claims

In the curved surface processing method of processing the workpiece surface of the workpiece with a processing machine,
The rotary machining tool having an arc cross section on the work surface is stopped and pressed with a constant load in a braked state and scanned, and the rotary work tool is scanned along the work surface. the Rukoto allowed to acquire the displacement of the pressing direction of this rotary machining tool by the position sensor, then the surface to be processed with respect to the coordinate system having from the acquired pressure direction of displacement of the machine get the positional relationship, and curved surface machining method characterized by processing the surface to be processed by the rotary machining tool based on the obtained position relationship.

In the curved surface processing method of processing the workpiece surface of the workpiece with a processing machine,
The rotary polishing tool having an arc cross section on the work surface is stopped and pressed with a constant load in a braked state and scanned, and the rotary polishing tool is scanned along the work surface. the Rukoto allowed to acquire the displacement of the pressure direction before Symbol rotary polishing tool this by the position sensor, then the object to be processed with respect to the coordinate system having from the acquired pressure direction of displacement of the machine A first step of acquiring the positional relationship of the surface, and a processing origin is determined on the processing surface based on this value, and the rotary polishing tool that is in point contact with the processing surface is scanned by dwell time control. And a second step of correcting the shape of the curved surface.

3. The curved surface machining method according to claim 2, wherein in order to obtain the coordinates of the surface to be machined, scanning is performed by controlling two orthogonal axes of XY that are linear motion axes, and during polishing by dwell time control, machining is performed. A curved surface machining method, further comprising controlling the tilt posture so that the normal of the point and the pressure axis coincide with each other.

In the curved surface processing method of processing the workpiece surface of the workpiece with a processing machine,
The rotary grinding tool having an arc cross section on the work surface is stopped and pressed with a constant load in a braked state and scanned, and the rotary grinding tool is scanned along the work surface. the Rukoto allowed to acquire the displacement of the pressure direction before Symbol rotary grinding tool of this by the position sensor, then the processed surface with respect to the coordinate system having from the acquired pressure direction of displacement of the machine The first step of acquiring the positional relationship and the processing origin is determined on the processing surface based on this value, and then the movable block as the pressing shaft of the rotary grinding tool is moved in the pressing direction. A second step of creating a curved surface shape by giving a desired tool locus to the air slide body fixed to the air slide body and fixed in the pressure direction of the rotary grinding tool. With features Curved surface machining method that.

5. The curved surface machining method according to claim 1, wherein scanning of the tool for obtaining a position of the workpiece surface is performed in the vicinity of a vertex or a deepest portion of the curved surface of the workpiece surface. The curved surface processing method is characterized in that the position of the apex or the deepest part is determined from the top dead center or the bottom dead center of the two acquired data.

6. The curved surface machining method according to claim 5, wherein the position of the apex or the deepest portion is determined by obtaining an approximate curve by function fitting to the acquired data.

5. The curved surface machining method according to claim 1, wherein the scanning of the tool for obtaining the position of the work surface is performed until the tool is removed from the work surface and dropped. A curved surface machining method, wherein the position of the edge of the work surface or the side surface of the mold member is determined from the tool coordinates of the drop start point.

In a curved surface processing apparatus that processes the work surface of a work piece with a processing machine,
A rotary machining tool, a pressure mechanism for pressing at a constant load to the surface to be processed in a state in which braking to stop the rotation of the rotary machining tool, the rotary machining tool is placed with an arc cross-section is a movable movable block in the pressing direction, and a position sensor for detecting the position of the movable block, said rotary working tool by scanning by copying operation at a constant load to the workpiece surface, the output of the position sensor And means for acquiring a positional relationship of the processing surface with respect to a coordinate system of the processing machine,
A curved surface processing apparatus comprising: means for processing the surface to be processed with the rotary processing tool based on the acquired positional relationship.

In a curved surface processing apparatus that processes the work surface of a work piece with a processing machine,
A rotary machining tool having an arcuate cross-section, a pressure mechanism for pressing at a constant load to the surface to be processed in a state in which braking to stop the rotation of the tip of the rotary machining tool, said rotary working tool A movable block that is mounted and movable in the pressurizing direction , a position sensor that detects the position of the movable block , and a fixing that fixes the movable block at a specific position with respect to the air slide body that moves in the pressurizing direction. means, a positioning control mechanism for giving a depth of cut in the rotary working tool, the rotary machining tool is scanned by the scanning operation at a constant load to the workpiece surface, based on an output of the position sensor, the machine be transferred and means for obtaining the positional relationship of the surface to be processed with respect to the coordinate system, thereby subsequently generating a desired trajectory to the air slide body movable block is fixed, the tool path to the work surface with the Curved machining apparatus characterized by comprising a means.