JP4087259B2

JP4087259B2 - Positioning method of electrode lower guide in electric discharge fine hole machining

Info

Publication number: JP4087259B2
Application number: JP2003021392A
Authority: JP
Inventors: 博英
Original assignee: Sodick Co Ltd
Current assignee: Sodick Co Ltd
Priority date: 2003-01-30
Filing date: 2003-01-30
Publication date: 2008-05-21
Anticipated expiration: 2023-01-30
Also published as: JP2004230506A

Description

【０００１】
【発明の属する技術分野】
本発明は、放電細穴加工機において細穴加工電極の先端部を挿通して位置決め案内する電極下ガイドの被加工体上への位置決め設置方法及び前記位置決め設置を可能にした放電細穴加工機に関する。
【０００２】
【従来の技術】
放電細穴加工機の被加工体の真上位置に於いて細穴加工電極の先端部を挿通して案内する電極下ガイドとしては、前記挿通穿孔方向（通常Ｚ軸）に調整位置決め可能に固定してコラム等に取り付け構成されているものが普通であった（例えば、特許文献１参照。）。
【０００３】
近時、各種制御装置や数値制御装置等の発達普及により前記電極下ガイドを被加工体上のＺ軸方向の所定位置に半自動やプログラム等により自動位置決めすることが可能な放電細穴加工機等の提案が散見されるようになってきてる（例えば、前記特許文献１参照。）。
【０００４】
具体的には、自動化の第１段階として、例えば、電極ガイドの保持装置にサーボ送り機構を設け、電極先端を電極ガイドに挿入する前にサーボ送り機構のモータを作動して送りねじを回転させ、電極ガイドと被加工体との距離を目視しながら、電極保持装置を上下動させて電極ガイドの位置決めを行なうと言ったものである。
【０００５】
そして、その次の段階として、上述のサーボ送り機構に加えて電極ガイドの近傍に、非接触リニアセンサ等の距離検出手段を設け、数値制御装置によりサーボ送り機構を距離検出手段の情報に応じて自動的に作動させるように構成し、位置決めに際して電極ガイドと被加工体との距離が所定距離以下になると、非接触リニアセンサから距離に応じて電気信号が数値制御装置に出力され、数値制御装置はその信号を電極ガイドの位置フィードバック信号として処理し、モータの回転を減速させる。ついでリニアセンサの出力が予め設定しておいた基準値に達すると、数値制御装置はモータの回転を停止し、被加工体と電極ガイド間がサーボロックされて電極ガイドの位置決めが終了すると言ったものである。
【０００６】
【特許文献１】
特開平２−７１９３３号公報
【０００７】
【発明が解決しようとする課題】
上述の第１段階における作業者の目視やスキミ（すきまゲージ）により勘に頼りながら電極下ガイドを上下移動させてする位置制御は、例えば、約０．５ｍｍから１ｍｍ程度以内の所定値と言う微小値であるところから、下ガイドの被加工体上面における位置決定は、作業性が悪く、熟練を要し、さらに誤操作により下ガイドを被加工体上面と干渉させてしまい、細穴加工機の機械精度を悪化させてしまうと言う問題があった。
【０００８】
また、上述第２段階のものは、電極下ガイドの近傍に設けることが可能で、該下ガイドの下端面と相対向する被加工体表面間の微小距離を、微小単位の刻みで高精度に検出して制御信号を出力し得る非接触のリニアセンサとして適当なものが無く、その実現は、今日、なお、難しいものである。
【０００９】
従って本発明は、放電細穴加工機の電極下ガイドを被加工体上面上に位置決めするとき、作業者が干渉を気にしながら下ガイド軸（Ｗ軸又は第１の昇降軸送り機構）を注意深く操作していたのを、電極下ガイドを被加工体所定位置の上面２〜３ｍｍの位置へ降ろして来て、電極下ガイド位置決めのＮＣプログラムをスタートさせれば、以後自動的に作動して電極下ガイドの位置決めが行なわれるようにすることにある。
【００１０】
【課題を解決するための手段】
前述の本発明の目的は、（１）放電加工機のコラムに第１の昇降軸送り機構を介してＷ軸スライダを設け、放電加工時には停止状態に保持される前記Ｗ軸スライダに、第２の昇降軸送り機構を介してＺ軸スライダを設け、該Ｚ軸スライダに細穴加工電極を取り付けた加工ヘッドを設け、該細穴加工電極の先端部を挿通して被加工体直上で位置決め案内する電極下ガイドを前記Ｗ軸スライダの下端部に取り付けた放電細穴加工機の前記電極下ガイドを被加工体の上面上の所定長の位置に位置決めする方法において、
前記電極下ガイドの下端面と対接して加工電極の先端と接触感知する接触感知電極を配置した状態で、
（ａ）前記Ｗ軸スライダを第１の昇降軸送り機構により所望に引き上げ、加工電極を加工ヘッドに取り付ける工程と、
（ｂ）前記細穴加工電極の下方先端を前記第２の昇降軸送り機構によりＺ軸スライダを降下させて前記電極下ガイドに完全挿通でない所望の状態に挿入調整する工程と、
（ｃ）放電加工電源の被加工体側の端子に接続される前記接触感知電極を、前記電極下ガイド下端面と相対的に対接せしめる工程と、
（ｄ）前記２第の昇降軸送り機構によりＺ軸スライダを降下させ、細穴加工電極の先端と前記接触感知電極とを接触感知させて前記加工電極の先端を電極下ガイドの下端面に位置決めする工程と、
（ｅ）前記電極下ガイドと接触感知電極との対接を解除し、前記第２の昇降軸送り機構によりＺ軸スライダを降下させ、細穴加工電極先端を電極下ガイドの下端面の位置から下方に所定長送り出す工程と、
（ｆ）前記第１の昇降軸送り機構によりＷ軸スライダを降下させ細穴加工電極の先端と被加工体表面とを接触感知させ、電極下ガイド下端面を被加工体表面上の前記所定長の位置に位置決めする工程と、
（ｇ）前記第２の昇降軸送り機構によりＺ軸スライダを前記所定長より僅かに短い長さ引き上げる工程と、
（ｈ）前記第１の昇降軸送り機構によりＷ軸スライダを、前記所定長よりも僅かに短い長さよりもさらに僅かに短い長さ降下させる工程と、
から成ることを特徴とする放電細穴加工機における電極下ガイドの位置決め方法とすることにより達成することができる。
【００１１】
また、前述の本発明の目的は、（２）前記（ｅ）工程中の電極ガイドと接触感知電極との対接を解除した後、又は前記（ｅ）工程の後、前記Ｚ軸スライダの加工ヘッドを、被加工体表面上の平面（ｘｙ）方向の所定の位置に位置決めする工程を有することを特徴とする請求項１に記載の放電細穴加工機における電極ガイドの位置決め方法とすることにより達成される。
【００１２】
また、前述の本発明の目的は、（３）上記（ａ）工程の引き上げ位置がＷ軸スライダ最上位位置で、上記（ｂ）工程の完全挿通でない所望の状態の挿入調整が電極下ガイドの下端面迄の完全挿通位置から所定の微小長さ引き上げた位置であることを特徴とする請求項１又は２に記載の放電細穴加工機における電極下ガイドの位置決め方法とすることにより達成される。
【００１３】
又、前述の本発明の目的は、（４）前記放電加工電源の被加工体側の端子に接続される接触感知電極が、前記電源への接続リード線手段を有する人手によって移動設置可能な金属板片であることを特徴とする請求項１、２又は３に記載の放電細穴加工機における電極下ガイドの位置決め方法とすることにより達成される。
【００１４】
また、前述の本発明の目的は、（５）前記（ｅ）工程における加工電極先端の電極下ガイドの下端面の位置から下方への送り出し所定長が、電極下ガイドの下端面と被加工体表面位置との間の距離として確認した後に送り出し操作が行なわれるものであることを特徴とする請求項１、２、３又は４に記載の放電細穴加工機における電極下ガイドの位置決め方法とすることにより達成される。
【００１５】
また、前述の本発明の目的は、（６）前記（１）において、前記（ｇ）工程の第２の昇降軸送り機構によるＺ軸スライダ、即ち加工電極の引き上げと、前記（ｈ）工程の第１の昇降軸送り機構によるＷ軸スライダの降下作動とを同時に行なわせるものであることを特徴とする放電細穴加工機における電極下ガイドの位置決め方法とすることにより達成される。
【００１６】
また、前述の本発明の目的は、（７）放電加工機のコラムに第１の昇降軸送り機構を介してＷ軸スライダを設け、放電加工時には停止状態に保持される前記Ｗ軸スライダに、第２の昇降軸送り機構を介してＺ軸スライダを設け、該Ｚ軸スライダに細穴加工電極を取り付けた加工ヘッドを設け、該細穴加工電極の先端部を挿通して被加工体直上で位置決め案内する電極下ガイドを前記Ｗ軸スライダの下端部に取り付けた放電細穴加工機において、
前記第１及び第２の各昇降軸送り機構に設けた各スライダの昇降移動位置を検出して各送り機構を制御する位置検出装置と、
前記細穴加工電極先端と、電極下ガイドに対接する接触感知電極及び被加工体表面との各接触を感知して位置決め信号を出力する接触感知装置と、
前記第１及び第２の各昇降軸送り機構を所定の順序で昇降移動させると共に電極先端との接触感知により接触感知装置から出力する信号により制御する電極下ガイドの被加工体直上位置決めプログラムの記憶媒体と、
該記憶媒体から所定のプログラムを読み出し前記第１及び第２の昇降軸送り機構の作動を制御するＣＮＣ制御装置とを設けて成る、
前記（１）乃至（６）のいずれか１に記載の放電細穴加工機における電極下ガイドの位置決め方法の実施に使用する放電細穴加工機とすることにより達成されるものである。
【００１７】
【発明の実施の形態】
図１及び図２は、本発明の電極下ガイドの位置決め方法を実施する細穴放電加工機１の一実施例を示す概略構成の側面図と正面図で、２はベッド、４はベッド２上において水平方向の一軸であるＹ軸方向の軸送り機構３により移動するサドル、６はサドル４上において直角なＸ軸方向の送り機構５により移動するテーブル、７はテーブル６上に設けられた加工槽、８は被加工物１を載置する載物台、９は基準球９Ａの外に、後で説明するように水平面状の接触感知電極９Ｂを有し、所望の位置に設けられる位置決め基準球装置である。
【００１８】
１０はコラムで、図示では省略されているが、ベッド後部などのベッド２上、またはベッド２側部に立てられて設けられる。１１は、Ｗ軸スライダ１２をコラム１０に対してＷ軸に送る第１の昇降軸送り機構で、コラム１０前面にレールと軸受から成る直線案内１１Ｃによって取り付けられ、Ｗ軸にボールねじ１１Ａによって昇降軸送り可能に設けられたＷ軸スライダ１２を、コラム１０のブラケットに取り付けた回転形のサーボモータ１１Ｂによって駆動し、位置と送り作動がエンコーダ１１Ｄの検出フィードバック信号により制御される。
【００１９】
１４は、細穴加工用のパイプ電極１８を取り付けた加工ヘッド２０を保持するＺ軸スライダで、前記Ｗ軸スライダ１２と一体のスライダ本体１２Ａの前面に、レールと軸受との組合せから成る直線案内装置１４ＡによってＷ軸と平行なＺ軸に昇降軸送り可能に第２の昇降軸送り機構１３を介して設けられ、該第２の昇降軸送り機構１３の駆動源は、図示実施例の場合、Ｗ軸スライダ本体１２Ａの前面に磁石片をＺ軸方向に並べて取り付けた磁石板１３Ａと、該磁石板１３Ａと微小間隔を置いて相対向するようにＺ軸スライダ１４に取り付けられたＺ軸方向に間隔を置いて列設した磁芯磁極と巻回コイルの組合せから成る電磁石１３Ｂを設けたリニアモータから構成されている。そして、このリニアモータ１３によるＺ軸スライダ１４の送り位置決めは、Ｗ軸スライダ本体１２ＡとＺ軸スライダ１４に設けられるリニアスケルとセンサとから成るリニアエンコーダ１３Ｄにより検出して制御される。
【００２０】
細穴加工電極１８は通常φ０．３ｍｍ前後で長さが最大約２５０ｍｍ前後であり、より細い電極の場合には、電極ホルダ１８Ａに予め取り付け一体化された状態で、加工ヘッド２０の加工主軸１６に交換等して取り付けられ、回転駆動装置１５により回転させられる。
【００２１】
２１及び２４は、加工電極１８を先端側から挿通して位置決めと案内をする電極ガイドであり、２１が被加工体１の真上の近接位置で、電極１８先端を挿通して位置決めする電極下ガイド、２４は必要に応じＺ軸方向に移動可能にＷ軸スライダ本体１２Ａに対し、又はＺ軸スライダ１４側に保持されていてもよい中間ガイドである。前記電極下ガイド２１は、前記Ｗ軸スライダ本体１２Ａの下端部にブラケット２３を介し、該ブラケット２３に保持されたガイド取り付けベース２２の取り付け穴に、下方端が取り付けベース２２の下面よりも所定寸法、正確に突出する状態となるようにセットされるものである。
【００２２】
２５は放電細穴加工用の電源で、一方の端子が載物台８から被加工体１に、他方の端子が電極ホルダ１８Ａから加工電極１８へと接続され、放電加工状態検出装置２６によって検出された加工状態信号を、放電細穴加工用のＣＮＣ装置２７に、フィードバックすることにより、加工用電源２５は前記検出装置２６及びＣＮＣ装置２７により制御される。
【００２３】
２８は接触感知装置で、基準球９Ａ及び接触感知電極９Ｂを有する基準球装置９は通常被加工体１と同じ側の端子に、そして他方の端子が、電極ホルダ１８Ａを介して加工電極１８に接続され、加工電極１８と被加工体１又は基準球９Ａ若しくは接触感知電極９Ｂ間の位置決め又は位置検出を、対応駆動モータ３、５、１１Ｂ、又は１３の作動により行なう作動を、接触感知装置２８の検出信号のフィードバックによりＣＮＣ装置２７は作動して停止や原位置復帰作動又は検出位置の記憶するなどの制御する。なお、２９は放電細穴加工の各種のプログラムや指令等の記憶装置、３０はキーボードや外部記憶媒体の読み込み等の入力装置、３１はＣＲＴ等の表示装置である。又駆動モータ３及び５の各軸についても、リニア形又はロータリィ形の位置検出器が設けてあること当然である。
【００２４】
図３は、前記電極下ガイド２１の一実施例の縦断面図で、図において電極下ガイド２１は、外周形状が全体として長尺の円柱状体で、外筒２１Ｄは、例えば、ステンレス製で、内筒２１Ｅはセラミックス製のスリーブであり、電極１８を挿通案内する案内孔２１Ａと、挿通位置決めするルビー製などのダイスガイド２１Ｂを１個又は図示のように所定の間隔を置いて複数個有する。前記ダイスガイド２１Ｂの少なくとも下端部のガイド２１Ｂ−１は、後述するように、該電極下ガイド２１の下端面２１Ｃが位置決め基準面として使用されるので、前記ダイスガイド２１Ｂ−１との位置は下端面２１Ｃとの水平度を含め精密に位置出ししてあり、案内孔２１Ａとの同芯精度も出してある。
【００２５】
図４は、前記電極下ガイド２１が、前記被加工体１又はテーブル６等に設置された基準球装置９の接触感知電極９Ｂと加工電極１８先端が対接し得るようにガイド取り付けベース２２に設置された一実施例の要部拡大断面図である。電極下ガイド２１は、Ｗ軸スライダ本体１２Ａにガイド取り付けベース２２を取り付ける連結ブラケット２３に、さらには取り付けベース２２に適宜のセラミックスやエンジニアリングプラスチック、さらにそのスリーブやブッシングなどを用いて、電気的に絶縁した状態に取り付けられている。
【００２６】
そして、電極下ガイド２１のダイスガイド２１Ｂと同芯の案内孔２１Ａは、下端面２１Ｃと精密に直角で取り付けベース２２に鉛直軸に平行にして、取り付けベース２２の基準である下端面から所定長突出させて取り付けられている。そして、この電極下ガイド２１の下端面２１Ｃと対接させられる接触感知電極９Ｂは、少なくとも設置状態で鉛直方向に数ｍｍ程度弾性変位可能な支持体９Ｃを介して基準球装置９に取り付けられているが、電極下ガイド２１の下端面２１Ｃと対接可能な位置なら別の場所であっても良く、又基準球装置９と別個独立の物であっても良い。
【００２７】
図５は、前記接触感知電極９Ｂの支持体９Ｃの一例を示す部分拡大断面図で、図示しない適宜の設置台等に設けた支柱９Ｃ１の上端に函体９Ｃ２を取り付け、接触感知電極９Ｂの下面に取り付けた支柱９Ｃ３の下端に球体９Ｃ４を設け、前記支柱９Ｃ３を函体９Ｃ２の上蓋に設けた穴９Ｃ７に嵌挿して軸方向に案内させ、前記球体９Ｃ４を函体９Ｃ２内で上下のスプリング９Ｃ５、９Ｃ６により前記軸方向に弾性変位可能に保持させたものである。かかる構成によれば、電極下ガイド２１と接触感知電極９Ｂとの平面方向の位置合わせをしてＺ軸方向のジョグ送りにより数ｍｍ程度以内の間隔の対接状態として、更にＷ軸に送る第１の昇降軸送り機構１１を操作して、接触感知電極９Ｂ上面に電極下ガイド２１の下端面が適度に接触するように操作することは比較的容易であり、この接触操作による両者の干渉によって、接触感知電極９Ｂ及び電極下ガイド２１又はその取り付けベース２２などのホルダ等が、精度的ダメージを受ける可能性を充分低くすることができる。
【００２８】
図６は、前記接触感知電極９Ｂ及びその支持構造の簡易化を計った一例の要部側面図で、前記接触感知電極９Ｂが、銅又は銅合金板等をほぼ「く」字状にに弾性変形させ、一端側を支柱９Ｃ１に固定し、他端側の外側面９Ｄを電極下ガイド２１の下端面２１Ｃと対接させようとするものである。
【００２９】
以上のような細穴放電加工機の構成において、電極下ガイド２１の被加工体１加工部上面位置に対する位置決めは次のように行なわれる。
先ず、Ｗ軸スライダ１２及びスライダ本体１２Ａを第１の昇降軸送り機構１１により所望に引き上げ、加工ヘッド２０に細穴加工電極１８又は細穴加工電極１８を取り付けた電極ホルダ１８Ａを取り付ける。この場合、加工寸法と機械仕様などとの関係にもよるが、前記Ｗ軸スライダ１２等は最上部位置、通常上部リミット迄引き上げ、必要に応じエンコーダ１１Ｄの原点のリセット設定、及びその記録をする。
【００３０】
次いで、第２の昇降軸送り機構１３を操作して又はプログラムの実行により前記細穴加工電極１８を先端から中間ガイド２４、そして電極下ガイド２１の案内孔２１Ａ及びダイスガイド２１Ｂへと通して行くが、前記電極下ガイド２１には、ガイド長さの８０％程度挿通した状態として停止させる。しかして、この場合、電極下ガイド２１に対する加工電極１８の挿通は、加工電極１８先端を、一旦完全に挿通させた後、所望微小長さ電極下ガイド２１の下端面２１Ｃから引っ込めた状態と作動させて設定するのが良い。
【００３１】
次いで、放電加工電源２５の被加工体１側の端子に接続されている前記の接触感知電極９Ｂを、電極下ガイド２１の下端面２１Ｃに対接させるように、一方に対する他方の水平方向の位置を相対的に移動させるが、この場合Ｗ軸スライダ１２は前述の如く最上位の位置にあるから、電極１８の先端を電極下ガイド２１の下端面２１Ｃの位置から所定長延出させる後工程の前記所定長を考慮すると、降下は行なうにしても制限されるので、基準球装置９に対して何等かの架台などを必要とする場合が生ずる。予め定めた架台等を設けて位置決め出来ない場合には、銅板等の接触感知電極９Ｂを手動操作等により電極下ガイド２１の下端面２１Ｃに或る程度押し付けるようにして対接させ、次工程へ進むことが考えられる。
【００３２】
しかして、電極下ガイド２１の下端面２１Ｃに接触感知電極９Ｂを対接させた状態で、加工電極１８と接触感知電極９Ｂ間の接触感知装置２８をオンにして接触感知位置決め機能を起動させ、第２の昇降軸送り機構１３によりＺ軸スライダ１４を降下させ、加工電極１８の先端を接触感知電極９Ｂに接触により送りを停止させて、前記加工電極１８の先端を電極下ガイド２１の下端面２１ＣのＺ軸方向の位置に一致位置決めする。この場合加工電極１８の先端は前記下端面２１Ｃに充分近い位置にあるように調整設定されているので、この接触感知の処理操作は十分迅速に行なうことが出来る。
【００３３】
次いで、前記電極下ガイド２１の下端面２１Ｃに対する接触感知電極９Ｂの対接を解除する操作を、接触感知電極９Ｂに対するｘｙ水平方向の位置の相対移動や前記接触感知電極９Ｂの設置部からの移動又は撤去などにより行い、第２の昇降軸送り機構１３によりＺ軸スライダ１４を予め定めた所定長、例えば、５０ｍｍ、降下させて加工電極１８の先端を電極下ガイド２１の下端面２１Ｃから前記所定長さ送り出し突出させる。この所定長の降下送りに際しては、加工電極１８の根元の電極ホルダ１８Ａと最上位の中間電極ガイド２４間の間隔及び、電極下ガイド２１の下端面２１Ｃと被加工体１表面間の間隔が前記所定長以上であることの予じめの確認が必要なること当然である。
【００３４】
ここで、前工程の電極下ガイド２１の下端面２１Ｃに対する接触感知電極９Ｂの対接解除の処理工程終了迄で、加工電極１８の軸（電極下ガイド２１の案内孔２１Ａの軸心）の位置が被加工体１表面上の所定の穴加工の位置又は、プログラム等により決めた所定の位置に在るかどうかをチェックして、相違している場合には、モータ３及び５を駆動して前記所定の位置に位置決めするよう作動させる。
【００３５】
次に、再び接触感知装置２８をオンにして接触感知位置決め機能を起動させると共に第１の昇降軸送り機構１１によりＷ軸スライダ１２及びスライダ本体１２Ａを降下させ、電極下ガイド２１の下端面２１Ｃから所定長垂下延出している加工電極１８の先端と被加工体１表面上の前記の所定の位置と接触感知により停止させ、前記電極下ガイド２１の下端面２１Ｃを被加工体１表面上所定位置上の前記所定長の位置に位置決めする。
【００３６】
次に、前記第２の昇降軸送り機構１３によりＺ軸スライダ１４を前記所定長よりも僅かに短い長さ、例えば、４９．５ｍｍ、引き上げて、加工電極１８の下方先端が電極下ガイド２１の下端面２１Ｃから前記僅かに短い長さ（０．５ｍｍ）突出した状態に設定する。
【００３７】
そして、最後に、第１の昇降軸送り機構１１によりＷ軸スライダ１２及びスライダ本体１２Ａを、前記所定長よりも僅かに短い長さよりも、更に僅かに短い長さ、例えば、４９ｍｍ降下させて停止させることにより、電極下ガイド２１の下端面２１Ｃは、被加工体１表面上所定位置上、例えば、１ｍｍの位置に、そして、加工電極１８の先端は、被加工体１表面上所定位置上から、例えば、０．５ｍｍ、離隔した位置に夫々位置決めされ、放電細穴加工を開始することができる。
【００３８】
なお、前述の場合、前記最終段階近くの段落［００３５］の第２の昇降軸送り機構１３によるＺ軸スライダ１４、即ち、加工電極１８の前記所定長より僅かに短い長さの引き上げと、前記最終工程の段落［００３６］の第１の昇降軸送り機構１１によるＷ軸スライダ１２、即ち電極下ガイド２１の前記所定値よりも僅かに短い長さより更に僅かに短い長さの降下送り作動とは、同時進行により行なわせて、位置決め時間の短縮を計ることもできる。
【００３９】
以上、本発明を図示した実施例を基に説明を加えたが、本発明の精神と範囲を逸脱することなく各部に多様な修正と変更を加えて実施が可能なこと勿論である。
例えば、図１及び図２で説明した放電細穴加工機の構成としては、特開２００２−２３３，９１６号公報に記載の放電細穴加工機のように、各部に種々の変更を加えたものによる実施が可能であり、又同様に電極下ガイドとしても、図３に例示の構成のものに限らないこと当然である。
【００４０】
【発明の効果】
以上詳述したように、本発明によれば、放電細穴加工機の加工電極に対する電極下ガイドを、加工軸のＺ軸を軸方向に移動位置決め配置する該Ｚ軸と平行なＷ軸のスライダの下端面に取り付け、該電極下ガイドの被加工体表面上における所望微小近接位置の位置決めを、前記Ｗ軸とＺ軸に対する各第１及び第２の昇降軸送り機構の作動制御により行なうようにしたので、電極下ガイド位置決めのＮＣプログラム作成により、ほぼ自動で行なうことが出来るようになり、作業者による誤操作問題や干渉による機械精度悪化等が無くなり、所望に位置決めして目的とする細穴加工が精度良く確実に行えるようになった。
【図面の簡単な説明】
【図１】本発明の電極下ガイドの位置決めの方法を実施する放電細穴加工機の一実施例の概略構成を示す側面図。
【図２】本発明の電極下ガイドの位置決めの方法を実施する放電細穴加工機の一実施例の概略構成を示す正面図。
【図３】電極下ガイドの一実施例の縦断面図。
【図４】電極下ガイドの設置状況の一実施例の要部拡大断面図。
【図５】接触感知電極の一実施例の要部拡大断面図。
【図６】接触感知電極の他の実施例における要部拡大側面図。
【符号の説明】
１被加工体
２ベッド
３、５モータ
４サドル
６テーブル
７加工槽
８載物台
９基準球装置
９Ａ基準球
９Ｂ接触感知電極
９Ｃ支持体
１０コラム
１１第１の昇降軸送り機構
１１Ａボールねじ
１１Ｂサーボモータ
１１Ｃ直線案内
１１Ｄロータリィエンコーダ
１２Ｗ軸スライダ
１２ＡＷ軸スライダ本体
１３第２の昇降軸送り機構
１３Ａ磁石板
１３Ｂ電磁石
１３Ｄリニアエンコーダ
１４Ｚ軸スライダ
１４Ａ直線案内
１５回転駆動装置
１６加工主軸
１８細穴加工電極
１８Ａ電極ホルダ
２０加工ヘッド
２１電極下ガイド
２１Ａ案内孔
２１Ｂダイスガイド
２１Ｃガイド下端面
２２ガイド取り付けベース
２３ブラケット
２５加工用電源
２６放電加工状態検出装置
２７ＣＮＣ装置
２８接触感知装置
２９記憶装置
３０入力装置
３１表示装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a positioning installation method on a workpiece of an electrode lower guide that positions and guides the tip of a thin hole machining electrode in an electric discharge fine hole machining machine, and a discharge fine hole machining machine that enables the positioning installation. About.
[0002]
[Prior art]
An electrode lower guide that guides the tip of the fine hole drilling electrode through the top of the workpiece of the electric discharge fine hole drilling machine is fixed so that it can be adjusted and positioned in the insertion drilling direction (usually the Z axis). And what was attached to the column etc. was normal (for example, refer patent document 1).
[0003]
Recently, development spread by the Z-axis direction capable of automatic positioning discharged to a predetermined position by the semi-automatic and programs small hole machining on the workpiece to the electrode lower guide such as the seed control device or a numerical control device The proposal of the machine etc. is sporadic (for example, refer to the above-mentioned patent document 1).
[0004]
Specifically, as the first stage of automation, for example, a servo feed mechanism is provided in the electrode guide holding device, and before the electrode tip is inserted into the electrode guide, the servo feed mechanism motor is operated to rotate the feed screw. The electrode guide is positioned by moving the electrode holding device up and down while observing the distance between the electrode guide and the workpiece.
[0005]
As a next step, distance detection means such as a non-contact linear sensor is provided in the vicinity of the electrode guide in addition to the servo feed mechanism described above, and the servo feed mechanism is controlled by the numerical controller according to the information of the distance detection means. When the distance between the electrode guide and the workpiece is equal to or less than a predetermined distance during positioning, an electrical signal is output from the non-contact linear sensor to the numerical controller according to the distance. Processes the signal as a position feedback signal of the electrode guide to decelerate the rotation of the motor. Then, when the output of the linear sensor reaches a preset reference value, the numerical control device stops the rotation of the motor and says that the positioning of the electrode guide is completed by servo-locking between the workpiece and the electrode guide. Is.
[0006]
[Patent Document 1]
JP-A-2-71933 gazette
[Problems to be solved by the invention]
The position control in which the lower electrode guide is moved up and down while relying on intuition by the operator's visual inspection and clearance (gap gauge) in the first stage described above is, for example, a minute value of about 0.5 mm to about 1 mm. Therefore, determining the position of the lower guide on the workpiece upper surface is poor in workability, requires skill, and causes the lower guide to interfere with the workpiece upper surface due to an erroneous operation. There was a problem that accuracy would be deteriorated.
[0008]
Further, the second stage can be provided in the vicinity of the lower electrode guide, and the minute distance between the workpiece surface opposite to the lower end surface of the lower guide can be determined with high accuracy in increments of minute units. There is no suitable non-contact linear sensor that can detect and output a control signal, and its realization is still difficult today.
[0009]
Therefore, according to the present invention, when positioning the electrode lower guide of the electric discharge fine hole drilling machine on the upper surface of the workpiece, the operator carefully cares about the lower guide shaft (W axis or the first lifting shaft feed mechanism) while being concerned about interference. When the electrode lower guide is lowered to the position of 2 to 3 mm above the workpiece to be processed and the NC program for electrode lower guide positioning is started, the electrode is automatically operated thereafter. The purpose is to position the lower guide.
[0010]
[Means for Solving the Problems]
The objects of the present invention described above are as follows: (1) A W-axis slider is provided in a column of an electric discharge machine via a first lifting shaft feed mechanism, and the W-axis slider is held in a stopped state during electric discharge machining; A Z-axis slider is provided via a lifting / lowering axis feed mechanism, a machining head having a small hole machining electrode attached to the Z-axis slider, a positioning guide directly above the workpiece through the tip of the small hole machining electrode. In the method of positioning the electrode lower guide of the discharge fine hole drilling machine in which the electrode lower guide is attached to the lower end of the W-axis slider at a predetermined length on the upper surface of the workpiece,
In a state where the contact sensing electrode that contacts the lower end surface of the lower electrode guide and senses contact with the tip of the processing electrode is disposed,
(A) a step of pulling up the W-axis slider as desired by a first lifting axis feed mechanism and attaching a machining electrode to a machining head;
(B) a step of adjusting the insertion of the lower end of the narrow hole machining electrode to a desired state where the Z-axis slider is lowered by the second lifting shaft feed mechanism and is not completely inserted into the electrode lower guide;
(C) contacting the contact sensing electrode connected to the terminal on the workpiece side of the electric discharge machining power source relatively with the lower end surface of the lower electrode guide;
(D) The Z-axis slider is moved down by the second elevating shaft feed mechanism, and the tip of the fine hole machining electrode and the contact sensing electrode are contact-sensed to position the tip of the machining electrode on the lower end surface of the electrode lower guide. And a process of
(E) The contact between the lower electrode guide and the contact sensing electrode is released, the Z-axis slider is lowered by the second lifting shaft feed mechanism, and the tip of the narrow hole machining electrode is moved from the position of the lower end surface of the lower electrode guide. A process of feeding a predetermined length downward,
(F) The W-axis slider is lowered by the first elevating-axis feed mechanism so that the tip of the thin hole machining electrode and the surface of the workpiece are in contact with each other, and the lower end surface of the electrode lower guide is the predetermined length on the surface of the workpiece. Positioning to the position of
(G) a step of raising the Z-axis slider by a length slightly shorter than the predetermined length by the second lifting shaft feed mechanism;
(H) lowering the W-axis slider by a length slightly shorter than a length slightly shorter than the predetermined length by the first elevating-axis feed mechanism;
This can be achieved by a method for positioning the electrode lower guide in the electric discharge fine hole drilling machine characterized by comprising:
[0011]
The above-mentioned object of the present invention is to process the Z-axis slider after (2) releasing the contact between the electrode guide and the contact sensing electrode in the step (e) or after the step (e). 2. The electrode guide positioning method in the discharge fine hole drilling machine according to claim 1, further comprising a step of positioning the head at a predetermined position in a plane (xy) direction on the surface of the workpiece. Achieved.
[0012]
The object of the present invention described above is as follows. (3) The lifting position in the step (a) is the uppermost position of the W-axis slider, and insertion adjustment in a desired state that is not completely inserted in the step (b) It is a position where a predetermined minute length is pulled up from the complete insertion position to the lower end surface, and is achieved by the positioning method of the electrode lower guide in the electric discharge fine hole processing machine according to claim 1 or 2. .
[0013]
Further, the object of the present invention is as follows: (4) A metal plate in which a contact sensing electrode connected to a terminal on the workpiece side of the electric discharge machining power source can be moved and installed manually with a connecting lead means to the power source. It is achieved by adopting a method for positioning an electrode lower guide in an electric discharge fine hole drilling machine according to claim 1, 2 or 3, wherein the method is a piece.
[0014]
Further, the object of the present invention is as follows. (5) The predetermined length of the downward feeding from the position of the lower end surface of the electrode lower guide at the tip of the processing electrode in the step (e) is such that the lower end surface of the lower electrode guide and the workpiece 5. The method for positioning an electrode lower guide in an electric discharge fine hole drilling machine according to claim 1, wherein the feeding operation is performed after confirming the distance to the surface position. Is achieved.
[0015]
The object of the present invention is as follows. (6) In (1), the Z-axis slider, that is, the machining electrode is lifted by the second lifting shaft feed mechanism in the step (g), and the step (h) This is achieved by a positioning method of the electrode lower guide in the discharge fine hole drilling machine characterized in that the lowering operation of the W-axis slider is simultaneously performed by the first lifting shaft feed mechanism.
[0016]
The above-described object of the present invention is to provide (7) a W-axis slider provided in a column of an electric discharge machine via a first lifting shaft feed mechanism and held in a stopped state during electric discharge machining. A Z-axis slider is provided via a second lifting shaft feed mechanism, a machining head having a small hole machining electrode attached to the Z-axis slider, and the tip of the fine hole machining electrode is inserted to directly above the workpiece. In the discharge fine hole drilling machine in which the lower electrode guide for positioning and guiding is attached to the lower end of the W-axis slider,
A position detecting device for detecting the moving position of each slider provided in each of the first and second lifting shaft feeding mechanisms and controlling each feeding mechanism;
A contact sensing device that senses each contact between the tip of the narrow hole machining electrode, a contact sensing electrode that contacts the electrode lower guide, and a surface of the workpiece, and outputs a positioning signal;
The first and second lifting shaft feed mechanisms are moved up and down in a predetermined order, and stored in a positioning program directly above the workpiece of the lower electrode guide controlled by a signal output from the contact sensing device by sensing contact with the electrode tip. Medium,
Comprising only set the CNC control equipment for controlling the operation of said first and second lifting axis feed mechanism reads a predetermined program from the storage medium,
This is achieved by using an electric discharge fine hole drilling machine used for carrying out the method of positioning the electrode lower guide in the electric discharge fine hole drilling machine according to any one of (1) to (6) .
[0017]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 are a side view and a front view of a schematic configuration showing an embodiment of a fine hole electric discharge machine 1 for carrying out the positioning method of an electrode lower guide according to the present invention, where 2 is a bed and 4 is on a bed 2. , A saddle that is moved by a Y-axis direction feed mechanism 3 that is one horizontal axis in FIG. 6, a table 6 that is moved by a perpendicular X-axis direction feed mechanism 5 on the saddle 4, and a machining that is provided on the table 6. A tank, 8 is a mounting table on which the workpiece 1 is placed, and 9 is a positioning reference provided at a desired position, having a contact sensing electrode 9B in a horizontal plane in addition to the reference sphere 9A, as will be described later. It is a ball device.
[0018]
Reference numeral 10 denotes a column, which is not shown in the figure, but is provided on the bed 2 such as the rear of the bed or standing on the side of the bed 2. Reference numeral 11 denotes a first lifting shaft feed mechanism that feeds the W axis slider 12 to the W axis with respect to the column 10, and is attached to the front surface of the column 10 by a linear guide 11C composed of a rail and a bearing, and is lifted by the ball screw 11A on the W axis. A W-axis slider 12 provided so as to be capable of axial feed is driven by a rotary servo motor 11B attached to a bracket of the column 10, and the position and feed operation are controlled by a detection feedback signal of the encoder 11D.
[0019]
Reference numeral 14 denotes a Z-axis slider for holding a machining head 20 to which a pipe electrode 18 for fine hole machining is attached. A linear guide comprising a combination of a rail and a bearing is provided on the front surface of a slider body 12A integrated with the W-axis slider 12. The device 14A is provided via a second lifting shaft feed mechanism 13 so as to be able to feed the lifting shaft to the Z axis parallel to the W axis, and the drive source of the second lifting shaft feed mechanism 13 is the case of the illustrated embodiment. A magnet plate 13A having magnet pieces arranged side by side in the Z-axis direction and attached to the front surface of the W-axis slider main body 12A, and a Z-axis direction attached to the Z-axis slider 14 so as to face the magnet plate 13A with a small gap therebetween. The linear motor is provided with an electromagnet 13B composed of a combination of magnetic core magnetic poles and winding coils arranged at intervals. The feed positioning of the Z-axis slider 14 by the linear motor 13 is detected and controlled by a linear encoder 13D comprising a linear skeleton and a sensor provided on the W-axis slider body 12A and the Z-axis slider 14.
[0020]
The fine hole machining electrode 18 is usually around 0.3 mm in diameter and about 250 mm in length at the maximum. In the case of a thinner electrode, the machining spindle 16 of the machining head 20 is attached in advance to the electrode holder 18A. And is rotated by the rotary drive device 15.
[0021]
Reference numerals 21 and 24 are electrode guides for positioning and guiding the machining electrode 18 from the tip side, and 21 is a close position directly above the workpiece 1 and is located under the electrode for positioning by inserting the tip of the electrode 18. The guide 24 is an intermediate guide that may be held on the W-axis slider main body 12A or on the Z-axis slider 14 side so as to be movable in the Z-axis direction as necessary. The lower electrode guide 21 has a lower end at a lower end than a lower surface of the mounting base 22 in a mounting hole of the guide mounting base 22 held by the bracket 23 via a bracket 23 at the lower end of the W-axis slider main body 12A. It is set so that it protrudes accurately.
[0022]
Reference numeral 25 denotes a power source for electric discharge fine hole processing. One terminal is connected from the mounting table 8 to the workpiece 1 and the other terminal is connected from the electrode holder 18A to the machining electrode 18 and is detected by the electric discharge machining state detection device 26. The machining power supply 25 is controlled by the detection device 26 and the CNC device 27 by feeding back the machined state signal to the CNC device 27 for machining the electric discharge fine holes.
[0023]
Reference numeral 28 denotes a contact sensing device, and the reference sphere device 9 having the reference sphere 9A and the contact sensing electrode 9B is normally connected to the terminal on the same side as the workpiece 1 and the other terminal is connected to the processing electrode 18 via the electrode holder 18A. The contact sensing device 28 performs the operation of positioning or detecting the position between the machining electrode 18 and the workpiece 1 or the reference sphere 9A or the contact sensing electrode 9B by the actuation of the corresponding drive motor 3, 5, 11B or 13. By the detection signal feedback, the CNC device 27 is operated to perform control such as stopping, returning to the original position, or storing the detected position. Reference numeral 29 denotes a storage device for various programs and instructions for electric discharge fine hole machining, 30 denotes an input device for reading a keyboard and an external storage medium, and 31 denotes a display device such as a CRT. Of course, each axis of the drive motors 3 and 5 is provided with a linear or rotary type position detector.
[0024]
FIG. 3 is a longitudinal sectional view of an embodiment of the lower electrode guide 21. In the figure, the lower electrode guide 21 is a columnar body having a long outer peripheral shape as a whole, and the outer cylinder 21D is made of, for example, stainless steel. The inner cylinder 21E is a ceramic sleeve, and has one guide hole 21A for inserting and guiding the electrode 18 and a plurality of ruby-made die guides 21B for inserting and positioning at a predetermined interval as shown in the figure. . As will be described later, since the lower end surface 21C of the lower electrode guide 21 is used as a positioning reference surface, at least the lower end guide 21B-1 of the dice guide 21B is positioned below the dice guide 21B-1. It is positioned precisely including the level with the end face 21C, and the concentric accuracy with the guide hole 21A is also shown.
[0025]
FIG. 4 shows that the lower electrode guide 21 is installed on the guide mounting base 22 so that the contact sensing electrode 9B of the reference ball device 9 installed on the workpiece 1 or the table 6 and the tip of the machining electrode 18 can come into contact with each other. It is a principal part expanded sectional view of the done Example. The lower electrode guide 21 is electrically insulated by using a connecting bracket 23 for attaching the guide mounting base 22 to the W-axis slider main body 12A, and further using appropriate ceramics or engineering plastic, a sleeve or a bushing for the mounting base 22. It is attached to the state.
[0026]
A guide hole 21A that is concentric with the die guide 21B of the lower electrode guide 21 is precisely perpendicular to the lower end surface 21C and parallel to the vertical axis of the mounting base 22, and has a predetermined length from the lower end surface that is the reference of the mounting base 22. It is attached to protrude. The contact sensing electrode 9B brought into contact with the lower end surface 21C of the lower electrode guide 21 is attached to the reference ball device 9 via a support 9C that can be elastically displaced by about several millimeters in the vertical direction at least in the installed state. However, it may be a different location as long as it can be brought into contact with the lower end surface 21 </ b> C of the lower electrode guide 21, or may be a separate and independent one from the reference ball device 9.
[0027]
FIG. 5 is a partially enlarged cross-sectional view showing an example of the support 9C of the contact sensing electrode 9B. A box 9C2 is attached to the upper end of a support column 9C1 provided on an appropriate installation base (not shown), and the lower surface of the contact sensing electrode 9B. A sphere 9C4 is provided at the lower end of the column 9C3 attached to the column 9C3. The column 9C3 is inserted into a hole 9C7 provided in the upper lid of the box 9C2 to be guided in the axial direction. , 9C6 so as to be elastically displaceable in the axial direction. According to such a configuration, the lower electrode guide 21 and the contact sensing electrode 9B are aligned in the planar direction, and are in contact with each other within a few millimeters by jog feeding in the Z-axis direction . It is relatively easy to operate the lift shaft feed mechanism 11 of 1 so that the lower end surface of the lower electrode guide 21 is in proper contact with the upper surface of the contact sensing electrode 9B. It is possible to sufficiently reduce the possibility that holders such as the contact sensing electrode 9B and the lower electrode guide 21 or the mounting base 22 thereof will be damaged accurately.
[0028]
FIG. 6 is a side view of an essential part of an example in which the contact sensing electrode 9B and the support structure thereof are simplified. The contact sensing electrode 9B is elastically formed in a substantially “<” shape in a copper or copper alloy plate or the like. The one end side is fixed to the support column 9C1, and the outer side surface 9D on the other end side is brought into contact with the lower end surface 21C of the lower electrode guide 21.
[0029]
In the configuration of the fine hole electric discharge machine as described above, the positioning of the lower electrode guide 21 with respect to the upper surface position of the processed part 1 is performed as follows.
First, the W-axis slider 12 and the slider main body 12A are pulled up as desired by the first lifting shaft feed mechanism 11, and the fine hole machining electrode 18 or the electrode holder 18A to which the fine hole machining electrode 18 is attached is attached to the machining head 20. In this case, although depending on the relationship between the machining dimensions and the machine specifications, the W-axis slider 12 and the like are pulled up to the uppermost position, usually the upper limit, and the reset setting and recording of the origin of the encoder 11D is performed as necessary. .
[0030]
Next, by operating the second lifting / lowering axis feed mechanism 13 or by executing a program, the fine hole machining electrode 18 is passed from the tip to the intermediate guide 24, the guide hole 21A of the lower electrode guide 21 and the die guide 21B. However, about 80% of the guide length is inserted into the lower electrode guide 21 and stopped. Therefore, in this case, the machining electrode 18 is inserted into the lower electrode guide 21 after the tip of the machining electrode 18 is completely inserted and then retracted from the lower end surface 21C of the desired minute length electrode lower guide 21. It is good to set it.
[0031]
Next, the other horizontal position with respect to one of the contact sensing electrodes 9B connected to the terminal on the workpiece 1 side of the electric discharge machining power supply 25 is brought into contact with the lower end surface 21C of the lower electrode guide 21. In this case, since the W-axis slider 12 is at the uppermost position as described above, the tip of the electrode 18 is extended by a predetermined length from the position of the lower end surface 21C of the electrode lower guide 21. in view of the predetermined length, the drop is limited even if to do, it occurs may require etc. some kind of frame with respect to the reference sphere device 9. If positioning cannot be performed by providing a predetermined frame or the like, the contact sensing electrode 9B such as a copper plate is brought into contact with the lower end surface 21C of the lower electrode guide 21 by manual operation or the like, and the process proceeds to the next step. It is possible to proceed.
[0032]
Thus, with the contact sensing electrode 9B in contact with the lower end surface 21C of the lower electrode guide 21, the contact sensing device 28 between the processing electrode 18 and the contact sensing electrode 9B is turned on to activate the contact sensing positioning function. The Z-axis slider 14 is lowered by the second lift axis feed mechanism 13 to stop the feed by contacting the tip of the machining electrode 18 with the contact sensing electrode 9B, and the tip of the machining electrode 18 is moved to the lower end surface of the lower electrode guide 21. Positioned to coincide with the position of 21C in the Z-axis direction. In this case, since the tip of the machining electrode 18 is adjusted and set so as to be sufficiently close to the lower end surface 21C, this contact sensing processing operation can be performed sufficiently quickly.
[0033]
Next, the operation of releasing the contact of the contact sensing electrode 9B with the lower end surface 21C of the lower electrode guide 21 is performed by relative movement of the position in the xy horizontal direction with respect to the contact sensing electrode 9B or movement from the installation portion of the contact sensing electrode 9B. Alternatively, the Z-axis slider 14 is lowered by a predetermined length, for example, 50 mm, by the second lifting / lowering axis feed mechanism 13 to lower the tip of the processing electrode 18 from the lower end surface 21C of the electrode lower guide 21. The length is fed out and protruded. In the downward feeding of the predetermined length, the distance between the electrode holder 18A at the base of the machining electrode 18 and the uppermost intermediate electrode guide 24 and the distance between the lower end surface 21C of the lower electrode guide 21 and the surface of the workpiece 1 are as described above. Naturally, it is necessary to confirm in advance that the length is longer than the predetermined length.
[0034]
Here, the position of the axis of the machining electrode 18 (the axial center of the guide hole 21A of the lower electrode guide 21) until the end of the process of releasing the contact of the contact sensing electrode 9B with the lower end surface 21C of the lower electrode guide 21 in the previous process. Is in a predetermined hole machining position on the surface of the workpiece 1 or a predetermined position determined by a program or the like, and if they are different, the motors 3 and 5 are driven. Operate to position at the predetermined position.
[0035]
Next, the contact sensing device 28 is turned on again to activate the contact sensing positioning function, and the W-axis slider 12 and the slider main body 12A are lowered by the first lifting / lowering axis feed mechanism 11 from the lower end surface 21C of the electrode lower guide 21. The lower end surface 21C of the lower electrode guide 21 is stopped at a predetermined position on the surface of the workpiece 1 by stopping contact with the tip of the processing electrode 18 extending a predetermined length and the predetermined position on the surface of the workpiece 1. It is positioned at the position of the predetermined length above.
[0036]
Next, the Z-axis slider 14 is lifted by a length slightly shorter than the predetermined length, for example, 49.5 mm, by the second lifting / lowering axis feed mechanism 13, and the lower end of the processing electrode 18 is positioned on the lower electrode guide 21. It is set in a state where the slightly short length (0.5 mm) protrudes from the lower end surface 21C.
[0037]
Finally, the W-axis slider 12 and the slider body 12A are lowered by a length slightly shorter than the length slightly shorter than the predetermined length, for example, 49 mm, and stopped by the first lifting shaft feed mechanism 11. By doing so, the lower end surface 21C of the electrode lower guide 21 is at a predetermined position on the surface of the workpiece 1, for example, a position of 1 mm, and the tip of the processing electrode 18 is from a predetermined position on the surface of the workpiece 1. For example, it is positioned at a position separated by 0.5 mm, and the discharge fine hole machining can be started.
[0038]
In the above-described case, the Z-axis slider 14 by the second lifting shaft feeding mechanism 13 in the paragraph [0035] near the final stage, that is, the lifting of the processing electrode 18 to a length slightly shorter than the predetermined length, What is the descent feed operation of a length slightly shorter than the length slightly shorter than the predetermined value of the W-axis slider 12, that is, the electrode lower guide 21, by the first elevating axis feed mechanism 11 in the paragraph [0036] of the final process? The positioning time can be shortened by carrying out the simultaneous progress.
[0039]
Although the present invention has been described above based on the illustrated embodiment, it goes without saying that various modifications and changes can be made to the respective parts without departing from the spirit and scope of the present invention.
For example, the configuration of the electrical discharge fine hole drilling machine described with reference to FIGS. 1 and 2 is the same as the electrical discharge fine hole drilling machine described in Japanese Patent Laid-Open No. 2002-233916, with various changes made to each part. Of course, the electrode lower guide is not limited to the one illustrated in FIG. 3.
[0040]
【The invention's effect】
As described above in detail, according to the present invention, the electrode lower guide for the machining electrode of the electric discharge fine hole drilling machine moves and positions the Z axis of the machining axis in the axial direction and is a W-axis slider parallel to the Z axis. So that the desired minute proximity position of the electrode lower guide on the surface of the workpiece is controlled by controlling the operation of the first and second lift axis feed mechanisms with respect to the W axis and the Z axis. Therefore, the NC program for positioning the electrode lower guide can be performed almost automatically, eliminating the problem of operator error and the deterioration of machine accuracy due to interference. Can now be performed accurately and reliably.
[Brief description of the drawings]
FIG. 1 is a side view showing a schematic configuration of an embodiment of an electric discharge fine hole drilling machine that implements a method for positioning an electrode lower guide according to the present invention.
FIG. 2 is a front view showing a schematic configuration of an embodiment of an electric discharge fine hole drilling machine that implements the method for positioning an electrode lower guide according to the present invention.
FIG. 3 is a longitudinal sectional view of an embodiment of an electrode lower guide.
FIG. 4 is an enlarged cross-sectional view of a main part of an embodiment of an installation state of an electrode lower guide.
FIG. 5 is an enlarged cross-sectional view of a main part of one embodiment of a contact sensing electrode.
FIG. 6 is an enlarged side view of a main part in another embodiment of the touch sensing electrode.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Workpiece 2 Bed 3, 5 Motor 4 Saddle 6 Table 7 Processing tank 8 Platform 9 Reference ball apparatus 9A Reference ball 9B Contact sensing electrode 9C Support body 10 Column 11 1st raising / lowering axis feed mechanism 11A Ball screw 11B Servo Motor 11C Linear guide 11D Rotary encoder 12 W-axis slider 12A W-axis slider body 13 Second lifting shaft feed mechanism 13A Magnet plate 13B Electromagnet 13D Linear encoder 14 Z-axis slider 14A Linear guide 15 Rotation drive device 16 Main spindle 18 Narrow hole Processing electrode 18A Electrode holder 20 Processing head 21 Lower electrode guide 21A Guide hole 21B Die guide 21C Guide lower end surface 22 Guide mounting base 23 Bracket 25 Processing power supply 26 Electric discharge machining state detection device 27 CNC device 28 Contact sensing device 29 Storage device 30 Input Device 31 Display device

Claims

A W-axis slider is provided in a column of an electric discharge machine via a first lifting / lowering axis feed mechanism, and the W-axis slider held in a stopped state during electric discharge machining is connected to the Z-axis slider via a second lifting / lowering axis feed mechanism. A Z-axis slider is provided with a machining head having a small hole machining electrode attached thereto, and an electrode lower guide for positioning and guiding the tip of the fine hole machining electrode directly above the workpiece is provided at the lower end of the W axis slider. In the method of positioning the electrode lower guide of the electric discharge fine hole processing machine attached to the part at a predetermined length position on the upper surface of the workpiece,
In a state where the contact sensing electrode that contacts the lower end surface of the lower electrode guide and senses contact with the tip of the processing electrode is disposed,
(A) a step of pulling up the W-axis slider as desired by a first lifting axis feed mechanism and attaching a machining electrode to a machining head;
(B) a step of adjusting the insertion of the lower end of the narrow hole machining electrode to a desired state where the Z-axis slider is lowered by the second lifting shaft feed mechanism and is not completely inserted into the electrode lower guide;
(C) contacting the contact sensing electrode connected to the terminal on the workpiece side of the electric discharge machining power source relatively with the lower end surface of the lower electrode guide;
(D) The Z-axis slider is lowered by the second lifting / lowering axis feed mechanism, and the tip of the fine hole machining electrode and the contact sensing electrode are contact-sensed to position the tip of the machining electrode on the lower end surface of the electrode lower guide. And a process of
(E) The contact between the lower electrode guide and the contact sensing electrode is released, the Z-axis slider is lowered by the second lifting shaft feed mechanism, and the tip of the narrow hole machining electrode is moved from the position of the lower end surface of the lower electrode guide. A process of feeding a predetermined length downward,
(F) The W-axis slider is lowered by the first elevating-axis feed mechanism so that the tip of the thin hole machining electrode and the surface of the workpiece are in contact with each other, and the lower end surface of the electrode lower guide is the predetermined length on the surface of the workpiece. Positioning to the position of
(G) a step of raising the Z-axis slider by a length slightly shorter than the predetermined length by the second lifting shaft feed mechanism;
(H) lowering the W-axis slider by a length slightly shorter than a length slightly shorter than the predetermined length by the first elevating-axis feed mechanism;
A method for positioning an electrode lower guide in an electric discharge fine hole drilling machine, comprising:

After releasing the contact between the electrode guide and the contact sensing electrode in the step (e), or after the step (e), the processing head of the Z-axis slider is moved to a plane (xy) on the surface of the workpiece. The method for positioning an electrode guide in a discharge hole drilling machine according to claim 1, further comprising a step of positioning at a predetermined position in the direction.

The lifting position in the step (a) is the uppermost position of the W-axis slider, and the insertion adjustment in a desired state that is not completely inserted in the step (b) is a predetermined minute length from the complete insertion position to the lower end surface of the electrode lower guide. 3. The method for positioning an electrode lower guide in an electric discharge fine hole drilling machine according to claim 1, wherein the position is a raised position.

The contact sensing electrode connected to the terminal on the workpiece side of the electric discharge machining power supply is a metal plate piece that can be moved and installed manually by means of connecting lead wires to the power supply. Or the positioning method of the electrode lower guide in the electrical discharge fine hole processing machine of 3.

Sending operation after confirming the predetermined length of feeding downward from the position of the lower end surface of the electrode lower guide at the tip of the machining electrode in the step (e) as the distance between the lower end surface of the electrode lower guide and the workpiece surface position 5. The method of positioning an electrode lower guide in an electric discharge fine hole drilling machine according to claim 1, wherein:

In claim 1, the Z-axis slider by the second lifting / lowering axis feed mechanism in step (g), that is, the machining electrode is pulled up, and the W-axis slider is lowered by the first lifting / lowering axis feed mechanism in step (h). A method for positioning an electrode lower guide in an electric discharge fine hole drilling machine, wherein the operation is performed simultaneously.

A W-axis slider is provided in a column of an electric discharge machine via a first lifting / lowering axis feed mechanism, and the W-axis slider held in a stopped state during electric discharge machining is connected to the Z-axis slider via a second lifting / lowering axis feed mechanism. A Z-axis slider is provided with a machining head having a small hole machining electrode attached thereto, and an electrode lower guide for positioning and guiding the tip of the fine hole machining electrode directly above the workpiece is provided at the lower end of the W axis slider. In the electrical discharge fine hole drilling machine attached to the
A position detecting device for detecting the moving position of each slider provided in each of the first and second lifting shaft feeding mechanisms and controlling each feeding mechanism;
A contact sensing device that senses each contact between the tip of the narrow hole machining electrode, a contact sensing electrode that contacts the electrode lower guide, and a surface of the workpiece, and outputs a positioning signal;
The first and second lifting shaft feed mechanisms are moved up and down in a predetermined order, and stored in a positioning program directly above the workpiece of the lower electrode guide controlled by a signal output from the contact sensing device by sensing contact with the electrode tip. Medium,
Comprising only set the CNC control equipment for controlling the operation of said first and second lifting axis feed mechanism reads a predetermined program from the storage medium,
It claims 1 to discharge small hole machine to use in the practice of the electrode under the guide method of positioning the discharge small hole machining machine according to any one sixth.