JP4108968B2 - Method and apparatus for measuring a rolling tool - Google Patents

Description

を演算し、この求めたＤを転削工具１２の工具幅として最大幅ホールド回路６０に送出する。最大幅ホールド回路６０は、工具幅算出回路５８が求めた工具幅を記憶保持する（ステップ８３）。
【００４１】
その後、制御・演算部３０の信号処理部３４は、ＬＥＤ駆動制御部３２が予め設定されている回数ＬＥＤ２１を点灯させたか否か判断する（ステップ８４）。信号処理部３４は、ＬＥＤ２１の駆動が所定回数になっていない場合、ステップ８５に進み、ＬＥＤ２１の駆動時刻になったか否かを判断し、駆動時刻になっていないときには駆動時刻になるのを待つ。そして、信号処理部３４は、ＬＥＤ２１の駆動時刻になったと判断すると、ステップ８１に戻ってＬＥＤ駆動制御部３２にＬＥＤ２１を駆動する指令を与え、ＬＥＤ２１を点灯させて転削工具１２に平行光２６を照射し、ステップ８１〜ステップ８４の処理を行なう。
【００４２】
この実施形態の場合、ＬＥＤ２１の駆動間隔、すなわち、ＬＥＤ２１を点灯してから次の点灯までの時間を相互に異ならせてある。例えば、ＬＥＤ駆動制御部３２は、最初のＬＥＤ２１の駆動（点灯）を終了してから１０００パルス後に２回目の駆動を行なったとすると、３回目の駆動は、２回目の駆動が終了してから１００５パルス後に駆動し、４回目は３回目の駆動が終了してから１０１０パルス後に駆動するなど、以下同様にＬＥＤ２１駆動間隔を異ならせている。これは、一定間隔でＬＥＤ２１を点灯させた場合、ＬＥＤ２１の点灯周期と転削工具１２の回転周期とが同期し、常に同じ回転位相のところを測定するのを避けるためである。従って、ＬＥＤ２１の点灯周期を変えて複数回検出することにより、測定される転削工具１２の位相が測定ごとに異なることとなり、転削工具１２の真の刃径を確実に求めることができる。しかも、実施形態においては、パルス状の光を転削工具１２に照射し、転削工具１２の瞬間的な影２７の位置を検出するとともに、適宜の間隔で複数回検出するため、転削工具１２の瞬間、瞬間の位置を正確に求めることができ、振れ量の正確な値を得ることができる。
【００４３】
２回目以降におけるＬＥＤ２１の光の放射に同期した測定で、第１エッジ点検出回路５４が求めた第１エッジ点Ｅ₁ の値が前回求めた値よりも小さな値である場合、最小値ホールド回路６２は、今まで記憶保持していた値に代えて、第１エッジ点検出回路５４から新たに入力されたＥ₁ の値を記憶保持する。第１エッジ点検出回路５４が新たに求めたＥ₁ が今まで最小値ホールド回路６２の保持していたＥ₁の値以上である場合には、最小値ホールド回路６２は、記憶保持しているＥ₁の値を更新しない。また、最大値ホールド回路６４は、第２エッジ点検出回路５６が新たに求めたＥ₂ の値が今まで保持していた値よりも大きい場合、それを更新して記憶保持し、第２エッジ点検出回路５６が新たに求めたＥ₂の値が前に求めたＥ₂の値以下である場合、既に記憶保持している値をそのまま記憶保持し続ける。
【００４４】
一方、２回目以降の測定においても、工具幅算出回路５８は、第１エッジ点検出回路５４と第２エッジ点検出回路５６とが求めた第１エッジ点Ｅ₁と第２エッジ点Ｅ₂とから
【数２】

を演算し、求めたＤの値を最大幅ホールド回路６０に送出する。最大幅ホールド回路６０は、新たに入力した工具幅Ｄの値が記憶保持している値より大きい場合に更新して記憶保持し、新たに入力したＤの値が記憶保持している値以下である場合、今までの値をそのまま記憶保持する。
【００４５】
制御・演算部３０は、信号処理部３４が図３のステップ８４においてＬＥＤ制御駆動部３２によるＬＥＤ２１の駆動、点灯回数が所定値に達したと判断すると、ステップ８６に進んで転削工具１２の刃径と振れ量とを出力する。すなわち、信号処理部３４の最大幅ホールド回路６０は、記憶保持しているＤ（Ｄ_MAX）を転削工具１２の刃径（直径）として表示装置などに出力する。また、信号処理部３４の振れ幅算出回路６６は、最小値ホールド回路６２が記憶保持しているＥ₁の最小値Ｅ_1MINと、最大値ホールド回路６４が記憶保持しているＥ₂の最大値Ｅ_2MAXとを読み出し、転削工具１２の振れ成分の一種である振れを含んだ刃径Ｄ′を、
【数３】

のように演算して求め、表示装置などに出力する。
【００４６】
また、振れ幅算出回路６６が求めたＤ′の値は、最大幅ホールド回路６０の出力したＤ_MAXとともに振れ量算出回路６８に入力される。振れ量算出回路６８は、入力された刃径Ｄ_MAXと振れを含んだ刃径Ｄ′とから、転削工具１２の刃径の寸法を除去したスピンドルの振れによる転削工具１２の振れ成分である振れ量２Ｂを次式により算出し、表示装置等に出力する。
【数４】

【００４７】
このように実施形態においては、転削工具１２を実際に使用する回転状態における転削工具の振れ量２Ｂを求められるようになっているため、振れ量の経時的変化を観察したり、チャックごとの振れ量の大きさを比較するなどして、スピンドルの良否やチャックの良否などを判別することができる。また、実施形態においては、転削工具の実際に使用する回転速度における転削工具の振れを含んだ刃径Ｄ′が求められるようになっているため、この刃径Ｄ′に基づいて補正を工作機械に与えることにより、加工精度を向上することができる。
【００４８】
ところで、発明者等は、加工精度の向上を図るために研究し、種々実験を行なったところ、転削工具、特に切刃が螺旋状に形成してある転削工具においては、スピンドルに振れが存在する場合、転削工具１２の軸線に沿った方向で回転振れ量が周期的に変化する現象を見出した。そこで、この実施形態においては、転削工具１２に対して軸方向の振れの変化も測定するようになっている。このため、最大幅ホールド回路６０が出力した刃径であるＤ_MAX、振れ幅算出回路６６が出力した転削工具１２の振れを含んだ刃径Ｄ′、振れ量算出回路６８が求めた振れ量２Ｂの値は、図示しない記憶部に、転削工具１２の軸方向位置に対応して記憶される（図３ステップ８６）。そして、制御・演算部３４の信号処理部３４は、転削工具１２の軸方向の予め設定されている測定範囲のすべてについて測定を終了したか否かを判断する（ステップ８７）。
【００４９】
制御・演算部３０の信号処理部３４は、測定範囲のすべてについての測定が終了していない場合、送り制御装置１４に送り指令を出力し（ステップ８８）、ステップ８０に戻る。送り制御装置１４は、制御・演算部３０からの指令に基づいて、転削工具１２を軸方向に所定量移動させる。そして、信号処理部３４は、送り制御装置１４から転削工具１２を軸方向に所定量（例えば、０．１ｍｍ）移動させた旨の信号が入力すると、ステップ８０〜ステップ８７の処理を繰り返す。そして、信号処理部３４は、ステップ８７において測定範囲のすべてについて振れの測定が終了すると、ステップ８９において転削工具１２を軸線方向に移動させて測定したときの最大振れ量２Ｂ_MAXや、振れ量を含んだ転削工具の刃径の最大値Ｄ′_MAXなどを出力する。
【００５０】
図９は、信号処理部３４による転削工具１２の軸方向における振れ量の変動を求める処理の概略を示したものである。信号処理部３４は、送り制御部１４によって転削工具１２が所定量ずつ軸方向に送られると、転削工具１２の軸方向における各測定位置Ｚ（Ｚ₁〜Ｚ_n）に対応して、前記したように刃径Ｄ_MAX（Ｄ_MAX1〜Ｄ_MAXn）と振れを含んだ刃径Ｄ′（Ｄ′₁〜Ｄ′_n）とを求める。振れを含んだ刃径Ｄ′は、測定位置の情報Ｚとともに出力され、振れ量２Ｂの演算に供されるとともに、位相検出部における振れ量の転削工具の軸方向における変動を表す関数を求めるのに供される。また、振れを含まない刃径Ｄ_MAX は、振れを含んだ刃径Ｄ′とともに振れ量の演算とその変動を表す関数の演算とに供される。
【００５１】
振れ量２Ｂの演算は、転削工具１２の軸方向における各測定点Ｚにおける測定ごとに行なわれる。例えば、転削工具１２が２枚刃の場合、振れ量２Ｂの演算は、前記したようにＤ′−Ｄ_MAXによって求められる。そして、この求めた振れ量２Ｂは、最大値ホールドされ、振れ量の測定が転削工具１２の軸方向における振れの変動の１周期以上にわたって行なわれた場合、その最大値２Ｂ_MAXを、転削工具１２の精度誤差による振れや、ツールホルダ、コレットなどの形状誤差を含んだスピンドルの振れ量（以下、単にスピンドル振れ量という）Ｒ₀ として出力される。また、このスピンドルの振れ量Ｒ₀ を含んだ最大刃径Ｄ′_MAX（Ｄ_MAX＋Ｒ₀）が求められて出力される。
【００５２】
一方、エンドミルのように転削工具１２の長さが刃の捩じれの１周期より短い場合、信号処理部３４は、測定した転削工具の軸方向長さにおける振れ量２Ｂの最大値を出力と、振れを含んだ刃径の最大値Ｄ′（＝Ｄ_MAX＋２Ｂ）とを出力する。
【００５３】
転削工具１２の軸方向における振れの変動、および振れを含んだ刃径Ｄ′の変動は、発明者等の研究によると、正弦波状となっている。そして、変動する振れ量の周期は、刃径Ｄと切刃の捩じれ角θと刃数Ｎとの関数として表すことができる。このため、振れの変動を表す関数を求めるためには、予め刃の捩じれ角θと刃数Ｎとを与えておく。
【００５４】
関数の演算は、転削工具１２の軸方向における測定位置Ｚと、その測定位置Ｚに対応した刃径Ｄ_MAXと、振れを含んだ刃径Ｄ′、および予め与えられた刃の捩じれ角、刃数とを用いてＤ′の関数近似により、
【数５】

として求められる。また、この関数演算においては、振れの周期Ｔ（振れの変動の工具軸方向における１周期）が求められる。振れの変動の周期Ｔは、刃径をＤ、刃の捩じれ角をθ、刃数をＮとした場合、これらの関数であって、
【数６】

と表すことができる。
【００５５】
このようにして求めた振れを含んだ刃径Ｄ′の変動を示す関数と周期Ｔとは、最大振れ量（スピンドル振れ量Ｒ₀）と、スピンドルの不釣合い位置に対する転削工具１２の軸方向に沿った刃の位相αの算出に供される。
【００５６】
すなわち、発明者等の研究によると、スピンドルに振れがある場合、スピンドルの不釣合い位置に対する工具の刃の位相αと、工具の振れ量との間には一定の関係が存在する。この関係は、例えば転削工具１２の先端位置の場合、スピンドルの不釣合い位置に対して、転削工具１２の先端における刃の位相αが０度であると、転削工具１２の先端の振れ量が最大となる。すなわち、転削工具の軸方向に沿って正弦波状に変化する振れ量の腹の部分が工具の刃先位置となる。これに対して、スピンドルの不釣合い位置に対する工具先端の刃の位相αが９０度である場合、正弦波状に変動する振れ量の節の部分が転削工具１２の先端位置となり、ほとんど振れない。このことは、スピンドルの不釣合い位置に対する転削工具１２の軸方向における刃の位相との関係においても同様である。
【００５７】
従って、測定可能な転削工具１２の長さが刃の捩じれの１周期以上の長さを有していない場合であっても、前記のようにして求めた振れを含んだ刃径Ｄ′の変動を示す関数と、この関数の工具軸方向における周期Ｔとにより、転削工具１２の振れの最大値であるスピンドルの振れ量Ｒ₀と、転削工具１２の先端の振れ量とを求めることができる。そして、転削工具１２の先端の振れ量が求められれば、この先端振れ量のスピンドルの振れ量Ｒ₀に対する割合から、スピンドルの不釣合い位置に対する転削工具１２の先端における刃の位相αを求めることができ、工具軸方向に沿ったスピンドルの不釣合い位置に対する刃の位相もどうように求められる。そして、転削工具１２の装着状態からスピンドルの不釣合い位置も容易に求めることができる。
【００５８】
このように実施形態においては、転削工具１２を実際に使用する回転速度における転削工具１２の軸方向における振れの変動、振れを含んだ刃径の変動を求めることができるため、転削工具１２の使用時における実際の振れ量、実際の振れを含んだ刃径が得られ、これに基づいて補正を行なうことにより、加工精度を向上することができる。また、スピンドルの不釣合い位置に対する工具先端の刃の位相を求めることができるため、例えば、ボールエンドミルによる金型加工のように、転削工具の先端部のみを使用するような場合、スピンドルの不釣合い位置に対する転削工具先端の刃の位相を求め、転削工具の振れが大きいような場合に、転削工具を回転させてチャッキングし直すことにより、転削工具先端の振れを小さくすることにより加工精度を高めることができる。
【００５９】
また、前記実施形態においては、転削工具１２の軸方向に工具幅Ｄを求めているため、転削工具１２の加工誤差に基づく刃径の変動、すなわち転削工具１２の加工精度をも求めることができる。
【００６０】
図４は、２枚刃の転削工具１２を軸方向に移動させて測定した振れ量を模式的に示したものである。図４に示したように、転削工具１２の振れは、破線に示したように、転削工具の軸線に沿ってほぼ正弦波状に変化する。また、転削工具のチャックへの装着状態によっては、同図（１）と同図（２）とに示したように、転削工具１２の先端部における振れが最小になる場合がある。これは、前記したように、スピンドルの不釣合い位置に対する転削工具１２の先端における刃の位相によるものである。図４（１）に示したように、転削工具１２の先端において振れ量変動の節となる場合、スピンドルの不釣合い位置に対する先端の刃の位相が９０度のときである。また、同図（２）に示したように、転削工具１２の先端における振れの変動が最大となる場合は、スピンドルの不釣合い位置に対する工具先端の刃の位相が０度のときである。なお、振れ量の変化の周期Ｔは、転削工具１２の刃径をＤ、切刃のねじれ角をθ、刃数をＮとした場合、発明者等の解析によると、
【数７】

と表すことができる。
【００６１】
このように、実施形態においては、転削工具１２を軸方向に移動させて軸方向の複数箇所において振れ量を求めるようにしているため、転削工具１２の回転による振れ量の最大値、すなわち本当の振れ量と、振れを含んだ刃径の最大値とを確実に求めることができる。従って、これらの値を考慮した切削加工を行なうことにより、加工精度を向上することができる。
【００６２】
ところで、任意の基準点に対するエッジ点Ｅ₁またはエッジ点Ｅ₂のいずれか一方を求めることにより、偶数刃ばかりでなく、奇数刃の転削工具１２に対しても振れ成分である振れ量や振れを含んだ刃径の片側位置などを求めることができる。すなわち、図５に示したように、ある基準点、例えば図１の光センサ２５の上端を基準点とし、その点から影２７の上端（第１エッジ点Ｅ₁）までの距離ｘを、転削工具１２を軸線方向に移動させつつ、上記のようにして求める。そして、求めたｘの最大値ｘ_MAXと最小値ｘ_MINとの差から、転削工具１２の中心に対する半径方向片側の振れ量を算出することができる。
【００６３】
これにより、影２７の両端位置を検出して測定した２Ｂの値の半分に相当する値、すなわち転削工具１２の中心に対する片側の振れ量Ｂがｘ_MAX−ｘ_MINとして得られ、これを２倍することによって全体の振れ量２Ｂを得ることができる。また、前記した影２７の両端の位置を求める方法では、求めることができなかった刃数が奇数の場合においても、後述するように、振れ量２Ｂを求めることができる。
【００６４】
また、この影２７の片側の位置だけを検出する方法によって振れ量２Ｂを求める方法においても、転削工具１２の軸方向における振れの変動、スピンドルの振れ量、スピンドルの不釣合い位置に対する転削工具の刃の位相を求めることができる。図１０は、光センサ２５に投影された影２７の片側端位置を検出して軸方向の振れの変動を求める処理の概略を説明する図である。この場合、図２に示したように、影２７の片側端位置（第１エッジ点Ｅ₁）の値をｅとして出力させる。
【００６５】
すなわち、信号処理部３４は、転削工具１２の軸方向における各測定位置Ｚに対応して第１エッジ点の情報ｅ（ｅ₁〜ｅ_n）を求める。この求めた値ｅは、最大値ホールド回路と最小値ホールド回路とにおいて最大値ｅ_MAXと最小値ｅ_MINとが選択される。このｅ_MAXとｅ_MINとは、図５の説明におけるｘ_MAXとｘ_MINとに相当する。
【００６６】
次に、信号処理部３４は、これらの最大値と最小値との偏差ｇ_N（＝ｅ_MAX−ｅ_MIN）を求める（図６（４）参照）。このようにして求めた偏差ｇ_Nは、転削工具１２の軸方向における測定範囲が刃の捩じれの１周期より短い場合、その測定範囲における振れ量の変動値として出力される。また、測定範囲が転削工具の刃の捩じれの１周期以上である場合、予め与えられている刃数Ｎを用いてスピンドルの振れ量Ｒ₀が次式により求められる。
【数８】

ここにｋ_N は、刃数Ｎによって定まる定数である。発明者等の研究によると、
【数９】

として求められる。なお、数式９においてＮは刃数であって、Ｎ≧２である。ただし、１枚刃（Ｎ＝１）の場合は、Ｎ＝２とする。
【００６７】
また、信号処理部３４は、前記と同様にして刃の捩じれ角と刃数とが与えられてｅの変動に基づく関数近似により転削工具１２の軸方向における変動の状態を表す関数ｅ＝ｆ（Ｚ）と、その周期Ｔとを求める。そして、前記したと同様に、これらからスピンドルの振れ量Ｒ₀と、スピンドルの不釣合い位置に対する工具の軸方向に沿った各点における刃の位相αとを演算する。
【００６８】
なお、転削工具１２を軸方向に沿って移動させて振れ量を測定した場合、切刃の数によって検出される振れの軸方向変化のパターンが異なる。図６は、その状態を模式的に示したものである。同図（１）は１枚刃の振れの軸方向変化を示したものであり、同図（２）は直径方向のそれぞれに切刃を有する２枚刃の場合を示したものである。これらは、いずれも正弦波状に変化する曲線のピークの高さが転削工具１２の使用状態における実際の片側の振れ量と見なすことができ、工具の形状精度誤差による振れを含んだスピンドルの片側の振れ量（Ｒ₀／２＝Ｂ）となる。従って、振れを含んだ刃径Ｄ′は、転削工具１２の刃径Ｄに２Ｂを加えた値（Ｄ＋２Ｂ）となる。
【００６９】
図６（３）は、中心に対して９０度間隔で４枚の切刃を有する転削工具の軸方向における振れの変化を模式的に示したものである。この４枚刃の場合、図６（３）の左側に示したように、実線で示した１番目の刃による振れ量のピークと３番目の刃による振れ量のピークとの間に、破線で示した２番目の刃による振れ量のピークが現われ、３番目の刃によるピークと１番目の刃によるピークとの間に４番目の刃によるピークがくる。このため、実際に測定される振れ量の軸方向の変化は、図６（３）の右側のようになる。
【００７０】
また、同図（４）は、中心に対して１２０度間隔で３枚の切刃を有する転削工具の軸方向における振れの変化を示している。この場合にも、４枚刃の場合と同様に、各刃による振れ量の変化が図６（４）の左側に示したように相互に重なるため、実際に測定される振れ量の軸方向に沿った変化は、図６（４）の右側に示したようになる。
【００７１】
図６（３）、（４）のように、４枚刃または３枚刃の場合、図５に示したように、影の片側の位置を検出しただけでは振れ量を求めることができない。しかし、各刃による振れ量の軸方向の変化は、正弦波状に変化するため、前記したように、切刃の捩じれ角と刃数とがわかれば振れ量を容易に求めることができる。
【００７２】
なお、前記実施形態は、本発明の一態様の説明であって、これに限定されるものではない。例えば、前記実施形態においては、軸方向の振れの変化を求める場合に、転削工具１２を軸方向に所定量ずつ送り、送りを停止した状態で振れ量を求める場合について説明したが、転削工具１２の軸方向への移動をゆっくり連続しておこない、転削工具１２を移動させつつ振れを測定してその最大値を実際の振れ量としてもよい。すなわち、例えば転削工具１２が２枚刃の場合、転削工具１２を軸方向に移動させつつ図５に示したｘの値を求め、求めたｘの最大値と最小値とから得た振れ量を２倍して実際の振れ量としてもよい。また、刃数が偶数の場合、第１エッジ点Ｅ₁と第２エッジ点Ｅ₂とから振れ量を求める場合にも、転削工具１２を軸方向に移動させつつ第１エッジ点Ｅ₁の最小値と、第２エッジ点Ｅ₂の最大値とを求めることによって、同様に振れ量を求めることができる。
【００７３】
また、前記実施形態においては、転削工具１２の軸方向における振れ量の変動を求める場合に、転削工具１２を軸方向に移動させる場合について説明したが、光センサ２５側を移動させるようにしてもよい。また、前記実施形態においては、光源がＬＥＤ２１である場合について説明したが、光源はレーザダイオードなどであってもよい。
【００７４】
さらに、前記実施形態においては、ＬＥＤ２１によってパルス状の光を転削工具１２に照射し、光センサ２５の受光素子を順次切り替えて受光素子の出力信号を読み込む場合について説明したが、転削工具１２に光を連続的に照射するとともに、光センサ２５の各受光素子に対応してバッファを設け、任意のタイミングで各受光素子の出力を対応するバッファに同時に読み込み、これに基づいて振れを求めるようにしてもよい。
【００７５】
図７と図８は、実施例に係る振れ測定装置１０によって転削工具の回転振れを実測した結果を示したものである。
図７は、エンドミルに対する軸方向における振れを含んだ刃径Ｄ′の変化の状態を示したもので、横軸がエンドミルの回転軸方向の移動距離（軸方向移動量）をｍｍ単位で示してあり、縦軸がエンドミルの刃径（直径）をｍｍで示してある。使用したエンドミルは、外径（刃径）が０．９９０ｍｍの２枚刃であって、切刃の捩じれ角は３０度である。そして、エンドミルの回転速度は、２０００ｒｐｍである。また、図中実線の曲線は同じ条件下における解析による値であり、■が振れを含んだ刃径の実測値、すなわち図２に示した振れ幅演算回路６６の出力による値を示したものである。さらに、図７の破線は、エンドミルの外径の実測値、すなわち図２に示した最大幅ホールド回路６０の出力による値である。
【００７６】
図７に示されているように、振れを含んだ刃径、すなわち振れ量がエンドミルの軸線に沿って変化していることがわかる。そして、図７から得られたスピンドルの最大振れ量は、約１０μｍ（１．０００〜０．９９０＝０．０１［ｍｍ］）であった。
【００７７】
図８は、２枚刃のドリルの軸方向における振れを含んだ刃径の変化の状態を示したものであり、横軸がドリルの回転軸方向の移動距離（単位：ｍｍ）、縦軸が刃径（単位：ｍｍ）である。そして、使用したドリルは、外径が０．４０３ｍｍ、切刃の捩じれ角が３０度であり、ドリルの回転速度が１２０００ｒｐｍである。また、図中の実線はシミュレーションによる値、■は振れを含んだ刃径の実測値、破線がドリルの刃径の実測値である。
【００７８】
図８に示されているように、ドリルにおいても軸方向で振れを含んだ刃径（振れ量）が変化する。しかも、振れを含んだ刃径（振れ量）は、軸方向において周期的に変化する。
【００７９】
図１１は、スピンドルの不釣合い位置に対する転削工具１２の先端における切刃の位相と、振れを含む刃径（振れ量）との関係を示したものであって、横軸が工具先端からの距離（単位：ｍｍ）であり、縦軸が刃径（単位：ｍｍ）である。また、図中破線で示した曲線は、スピンドルの不釣合い位置に対する工具先端の刃の位相が０度の場合の解析値を示し、二点鎖線は同じく位相が４５度の場合、実線は位相が９０度の場合を示している。そして、図中の▲は同じく位相が０度の場合の実測値、×は位相が４５度の場合の実測値、●は位相が９０度の場合の実測値である。
【００８０】
図から明らかなように、２枚刃の転削工具の場合、転削工具の先端における振れは、スピンドルの不釣合い位置に対する工具先端の刃の位相が０度の場合に最大となり、位相が９０度のときに最小となる。そして、位相が４５度のときには、両者の中間となる。
【００８１】
このように、スピンドルに振れが存在すると、転削工具１２の振れが軸方向に周期的に変動し、スピンドルの不釣合い位置に対する転削工具１２の刃の位相と振れ量との間に一定の関係が存在する。このため、例えばエンドミルによる側面切削加工をすると、エンドミルの振れのパターンが加工した切削面に転写される。そこで、例えばエンドミル先端の振れ量を最大となるように刃の位相を調整してチャックに装着し、最初にエンドミルの挿入量を最大にして切削加工したのち、エンドミルを挿入位置が浅くなるように軸方向に少しずらし、エンドミルから切削面に転写された凸部を削るように再度切削し、このような切削工程を複数回繰り返すことによって、加工した切削面の平坦化がはかれ、加工精度を向上することができる。
【００８２】
【発明の効果】
以上に説明したように、本発明によれば、回転している転削工具に光を照射して転削工具の影を光センサの上に投影し、その影の両端の位置を求めるとともに、この影の両端位置を転削工具の軸方向に沿った複数位置で求めることにより、回転している転削工具の軸線に直交した方向の影の両端位置ついて、転削工具の軸方向における変動が得られる。従って、転削工具の軸線に沿って得られた影の投影位置の変動に基づいて、転削工具の刃径（直径）や転削工具の実際の振れ量、転削工具の振れを含んだ実際の刃径を求めることができる。このため、実際に使用する回転数における転削工具の軸線に沿った振れ量、振れを含んだ刃径を求めているため、実際に使用する回転数における転削工具の実際の振れ量が得られ、この振れ量を加工の際の参考とし、振れ量が大きい場合に転削工具を交換したり、スピンドルのメンテナンスや交換をするなどにより、加工精度を高めることができる。また、常に大きな回転振れを発生させるチャックの把握などによってチャックの良否を判定することができ、スピンドルとチャックとを組み合せた状態での良否を判断することが可能となる。さらに、実際に使用する回転速度における転削工具の振れを含んだ実際の刃径が得られるため、この刃径を考慮した補正を工作機械に与えることにより、加工精度を向上することができる。
【００８３】
また、本発明においては、影の投影位置を、基準位置に対する前記影の一側端を検出して行なうようにしているため、偶数の切刃を有する転削工具の場合ばかりでなく、刃径を求めることができない切刃の数が奇数の場合であっても、その実際の振れ量を正確、確実に求めることができる。従って、奇数刃を有する転削工具による加工精度を向上することが可能となる。
【００８４】
そして、転削工具の軸方向に沿って振れ量求めているため、この振れ量を最大の振れ量と比較することにより、スピンドルの不釣合い位置に対する転削工具の軸線に沿った各位置における刃の位相を容易に求めることができ、チャックに転削工具を装着する際に、刃の位相を調節することにより、転削工具の軸方向における使用位置の振れ量を調節することが可能であり、加工精度を向上することができる。
【００８５】
さらに、転削工具の軸線に沿って振れ量を求めているため、実際に使用する回転速度における転削工具の形状精度誤差による振れを含んだスピンドルの振れ量が、転削工具の最大振れ量として求めることが可能で、このスピンドル振れを監視することにより、スピンドルの良否、チャックの良否などの判定に利用することができる。
【図面の簡単な説明】
【図１】 本発明の実施の形態に係る転削工具の測定装置の概略ブロック図である。
【図２】 本発明の実施の形態に係る信号処理部のブロック図である。
【図３】 本発明の実施の形態に係る転削工具の振れ測定方法を説明するフローチャートである。
【図４】 転削工具の軸方向における振れ量の変化を模式的に示した説明図である。
【図５】 本発明の第２実施形態の係る転削工具の振れ測定方法を説明する図である。
【図６】 転削工具の軸方向における振れ量の変化の刃数による相違を説明する図である。
【図７】 実施の形態により測定したエンドミルの軸方向における振れを含んだ刃径の変化を示す図である。
【図８】 実施の形態により測定したドリルの軸方向における振れを含んだ刃径の変化を示す図である。
【図９】 実施の形態に係る影の両端位置に基づいて転削工具の軸方向における振れの変動を求める方法の説明図である。
【図１０】 実施の形態に係る影の片側端位置に基づいて転削工具の軸方向における振れの変動を求める方法の説明図である。
【図１１】 スピンドルの不釣合い位置に対する２枚刃の工具先端における刃の位相と転削工具の振れを含んだ刃径との関係を示す図である。
【符号の説明】
１０………転削工具測定装置、１２………転削工具、１４………送り制御装置、２０………検出部、２１………ＬＥＤ、２２………コリメートレンズ、２４………結像レンズ、２５………光センサ、３０………制御・演算部、３４………信号処理部、５３………投影位置検出部、５４………第１エッジ点検出回路、５６………第２エッジ点検出回路、５７………変動検出部、５８………工具幅算出回路、６０………最大幅ホールド回路、６６………振れ幅演算回路、６８………振れ量算出回路。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for directly measuring a cutting edge during rotation, such as a deflection amount and a blade diameter including the deflection due to rotation of a rotary cutting tool such as a drill or an end mill.
[0002]
[Prior art]
With recent technological innovations, electrical and electronic equipment such as electrical appliances and information and communication equipment has rapidly increased in performance and size, and parts and molds used in these products have become smaller and more precise. Is required. In order to cope with such a situation, the diameter and accuracy of rotary cutting tools (rolling tools) such as drills and end mills are reduced, and extremely high-precision cutting is required.
[0003]
In order to obtain high machining accuracy, it is important to grasp the state of the turning tool during rotation. In particular, runout accompanying the rotation of the turning tool has a great influence on machining accuracy. Moreover, the rotational runout of the turning tool varies depending on the state of the spindle that rotates the turning tool via the chuck, the manufacturing error, the state of mounting of the turning tool on the spindle chuck, and the like. Moreover, the turning tool must be replaced after it has been used to some extent because the blades wear. For this reason, in general, in the field of precision machining, every time the rolling tool is replaced, a rotational runout is obtained to obtain a predetermined machining accuracy.
[0004]
However, at present, in a machine tool using a rolling tool represented by a machining center, it is difficult to obtain rotational runout in a use state in which a mounted rolling tool is rotated at a high speed. The value obtained by the method is used as a substitute for rotational runout when using the turning tool.
[0005]
In the first method, a round bar is attached to a chuck instead of a rolling tool, the round bar is rotated, light is irradiated to the round bar from the side, and the amount of deflection is optically determined. As a second method, a turning tool is mounted on the chuck of the spindle, the dial gauge is brought into contact with the peripheral surface of the turning tool, and the spindle is rotated slowly by hand, etc. The maximum value of the change indicated by the dial gauge pointer at the position is read with the eye, and this value is used as the value of the turning tool runout.
[0006]
[Problems to be solved by the invention]
With the first method described above, it is possible to measure the shake while rotating the round bar at a high speed. However, since this method uses a round bar as a substitute for the rolling tool, the value of the obtained runout may be different from the runout in a state where the rolling tool is actually used. In addition, as described above, the rotational runout of the turning tool changes each time the turning tool is mounted on the spindle chuck, so high-precision machining can be achieved by substituting the runout obtained by rotating the round bar. Is difficult.
[0007]
In addition, the measurement of runout with the second dial gauge is because the dial gauge is brought into contact with the rolling tool, so the runout with the rolling tool rotated at high speed cannot be measured, and the spindle is rotated by hand. Can only obtain so-called static run-out. In the second method, since the dial gauge is brought into contact with the rolling tool, not only the cutting blade of the rolling tool may be damaged, but also a tool having a small diameter of 1 mm or less is broken. There is a risk that it cannot be measured.
[0008]
On the other hand, in Japanese Patent No. 2505534, light is irradiated from the side of a rotating milling tool, the shadow of the milling tool is projected onto a light receiving element, and the diameter of the milling tool (blade) is projected from the projected shadow. There has been proposed a tool detection device for obtaining a diameter) and a deflection amount.
[0009]
However, in the invention described in Japanese Patent No. 2505534, the rotating tool is continuously irradiated with light, and the shake is measured from the change in the output of the light receiving element during one rotation of the tool. However, only average runout can be obtained, it is impossible to know how much the real runout is, and it is difficult to sufficiently increase the processing accuracy.
[0010]
The present invention was made to eliminate the drawbacks of the prior art, so that the cutting edge during rotation, such as the amount of runout of a turning tool rotating at high speed and the blade diameter including runout, can be directly measured. The purpose is to do.
Another object of the present invention is to improve the machining accuracy of a turning tool.
[0011]
[Means for Solving the Problems]
The present inventors have studied to improve the machining accuracy, and as a result of conducting various experiments, when the runout occurs in the rolling tool, if the cutting edge is formed in a spiral shape, A phenomenon was found in which the amount of runout of the tool periodically changed sinusoidally along the axial direction of the milling tool. Further, the present inventors have found that the amount of deflection at the tip of the cutting tool has a certain relationship with the phase of the blade at the tip of the turning tool with respect to the unbalanced position of the spindle that rotates the turning tool. According to the study by the present inventors, for example, in the case of two blades, if the phase of the blade at the tip of the tool with respect to the unbalanced position of the spindle is 0 degree, the amount of deflection at the tip of the turning tool is maximized, and the phase is 90. If it is, the runout amount at the tip of the rolling tool is minimized (zero). The present invention has been made based on the above findings.
[0012]
  That is, the measuring method of the rolling tool according to the present invention,Chucked into the processing machineBased on the output signal of the optical sensor at a plurality of positions in the axial direction of the rolling tool by projecting the shadow of the rolling tool onto the optical sensor by irradiating light from the side of the rotating rolling tool. Detecting the positions of both ends of the projected shadow, and based on the positions of the detected ends of the shadow,A deflection component is obtained along the axial direction of the rolling tool, and the phase of the blade of the rolling tool with respect to the unbalanced position of the spindle that rotates the rolling tool based on the deflection component, the deflection amount of the spindle, and Ask for at least one ofIt is characterized by that.
[0013]
  In addition, the measuring method of the turning tool according to the present invention,Chucked into the processing machineBased on the output signal of the optical sensor at a plurality of positions in the axial direction of the rolling tool by projecting the shadow of the rolling tool onto the optical sensor by irradiating light from the side of the rotating rolling tool. The one side edge position of the shadow projected in the above is detected, and based on the one side edge position of the detected shadow,A deflection component is obtained along the axial direction of the rolling tool, and the phase of the blade of the rolling tool with respect to the unbalanced position of the spindle that rotates the rolling tool based on the deflection component, the deflection amount of the spindle, and Ask for at least one ofIt is characterized by that.
[0014]
In the above-mentioned rolling tool measuring method, both end positions of the projected shadow are detected based on the output signal of the optical sensor, and the diameter of the cutting tool is determined based on the detected both end positions of the shadow. Then, at least one of the amount of runout of the turning tool and the blade diameter including the runout of the turning tool can be obtained. Further, the one side end position of the projected shadow is detected based on the output signal of the photosensor, and the blade diameter including the runout of the rolling tool is detected based on the detected one side end position of the shadow. It is also possible to determine the position on one side.
[0015]
  And the measuring device of the rolling tool which implements the measuring method of the above-mentioned rolling tool changes the time interval and changes the pulsed light.Chucked into the processing machineA light source that irradiates the rotating cutting tool, a light sensor that projects the shadow of the turning tool by the light irradiated by the light source, and an optical sensor that outputs the light sensor. A projection position detector that detects at least one of both ends of the shadow;The optical sensor is used for the machining usage area of the rolling tool.Based on the projection position information of the shadow output by the feed section that moves relative to the axial direction and the projection position detection section,Used for processingA fluctuation detection unit for obtaining at least one of fluctuations in the amount of runout in the axial direction, fluctuations in the blade diameter of the rolling tool, and fluctuations in the blade diameter including runout of the rolling tool, and the fluctuation detection unit The turning with respect to the unbalanced position of the spindle for rotating the turning tool based on the fluctuation of the turning amount of the turning tool, the blade diameter of the turning tool or the fluctuation of the blade diameter including the turning of the turning tool. A phase detection unit that obtains at least one of the phase of the blade of the tool and the amount of deflection of the spindle.
[0016]
[Action]
In the invention as described above, the rotating tool is irradiated with pulsed light at different time intervals, for example, to project the shadow of the tool on the optical sensor. Find the position of both ends. Further, the positions of both ends of the shadow are obtained at a plurality of positions along the axial direction of the rolling tool. Thereby, the fluctuation | variation in the axial direction of a cutting tool is obtained about the both-ends position of the shadow of the direction orthogonal to the axis line of the rotating cutting tool. Therefore, based on the fluctuation of the projected position of the shadow obtained along the axis of the turning tool, the cutting tool's blade diameter (diameter), the actual amount of turning of the turning tool, and the turning tool's runout were included. The actual blade diameter can be determined.
[0017]
That is, as described above, since the runout of the rolling tool varies along the axial direction of the rolling tool, the runout amount at a certain point (one point) in the axial direction of the rolling tool can be measured as in the past. However, since it is impossible to determine whether the runout amount is the maximum runout amount or the minimum runout amount, the actual runout amount including the actual runout and runout in the portion used by the rolling tool It is impossible to know what the blade diameter is, and the processing accuracy cannot be sufficiently increased.
[0018]
On the other hand, in the present invention, since the amount of run-out along the axis of the turning tool at the actually used rotational speed and the blade diameter including the run-out are obtained, the turning tool at the actually used rotational speed is obtained. An actual runout amount can be obtained, and this runout amount can be used as a reference during machining. When the runout amount is large, the machining accuracy can be improved by changing the rolling tool or performing maintenance or replacement of the spindle. . Further, it is possible to determine the quality of the chuck by grasping the chuck that constantly generates a large rotational runout, and it is possible to determine the quality in a state where the spindle and the chuck are combined. Furthermore, since the actual blade diameter including the deflection of the turning tool at the actual rotation speed can be obtained, the machining accuracy can be improved by giving the machine tool correction in consideration of the blade diameter.
[0019]
In the present invention, since the shadow projection position is detected by detecting one side edge of the shadow with respect to the reference position, not only in the case of a rolling tool having an even number of cutting edges, the blade diameter Even if the number of cutting blades for which it is not possible to obtain is determined, it is possible to determine the one-sided position of the blade diameter including runout. Can be obtained accurately and reliably. Therefore, it is possible to improve the machining accuracy with the rolling tool having odd-numbered blades.
[0020]
As described above, the amount of deflection of the rolling tool periodically changes in a sinusoidal shape in the axial direction of the rolling tool. For example, in the case of two blades, the turning amount of the turning tool becomes maximum when the phase of the cutting tool blade with respect to the unbalanced position of the spindle is 0 degree, and becomes minimum when the phase is 90 degrees. . Therefore, by calculating the runout component such as the one-side position of the blade diameter including the runout amount and runout along the axis of the turning tool, and comparing this runout component value with the maximum runout component value, The phase of the blade at each position along the axis of the turning tool with respect to the balance position can be easily obtained. The amount of run-out, which is the run-out component at each position along the axis of the turning tool, has a fixed relationship with the phase of the cutting tool blade relative to the unbalanced position of the spindle, so the turning tool is mounted on the chuck. At this time, by adjusting the phase of the blade, it is possible to adjust the amount of deflection of the use position in the axial direction of the rolling tool, and it is possible to improve the machining accuracy.
[0021]
For example, when only the tip of the cutting tool is used, such as die processing by a ball end mill, the phase of the cutting tool tip relative to the unbalanced position of the spindle is obtained, and the deflection of the turning tool is large. In such a case, the machining accuracy can be increased by reducing the runout of the tip of the turning tool by rotating the turning tool and rechucking.
[0022]
Furthermore, since the amount of runout is calculated along the axis of the turning tool, the amount of runout of the spindle, including runout due to shape accuracy error of the turning tool at the actual rotation speed, is the maximum amount of runout of the turning tool. By monitoring this spindle run-out, it can be used to determine whether the spindle is good or bad, or whether the chuck is good or bad.
[0023]
In the present invention, the amount of spindle runout includes not only the runout of the spindle itself but also the runout due to the shape accuracy error of the turning tool and the runout based on the shape error of the tool holder, collet, etc. .
[0024]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of a measuring method and apparatus for a turning tool according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic block diagram of a turning tool run-out measuring apparatus according to the present invention. In FIG. 1, the shake measurement apparatus 10 includes a detection unit 20 and a control / calculation unit 30. The detection unit 20 includes an LED 21 that is a light source, a collimating lens 22, an imaging lens 24, an optical sensor 25, and the like.
[0025]
A turning tool 12 such as a drill or an end mill whose rotational runout is to be detected is disposed between the collimating lens 22 and the imaging lens 24. The LED 21 emits light for irradiating the turning tool 12. The light emitted from the LED 21 is converted into parallel light 26 by the collimating lens 22 disposed in front of the LED 21, and is irradiated from the side onto the cutting tool 12 inserted in the optical path of the parallel light 26.
[0026]
The imaging lens 24 receives the parallel light 26 emitted from the collimating lens 22, enlarges the shadow 27 by the cutting tool 12, and projects it onto the optical sensor 25. In the optical sensor 25, for example, a plurality of light receiving elements such as CCDs are linearly arranged from the upper side to the lower side in FIG. The turning tool 12 is rotated about an axis by a rotating device (spindle) (not shown) and can be moved in the axial direction by a feed control device 14 which is a feeding unit.
[0027]
The control / calculation unit 30 includes an LED drive control unit 32, a signal processing unit 34, a sensor output reading unit 36, an oscillation circuit 38, a reading pulse generation unit 40, and the like. The LED drive control unit 32 generates a drive signal for the LED 21 based on the reference pulse output from the oscillation circuit 38 according to a command from the signal processing unit 34, and drives the LED 21 in a pulsed manner as will be described in detail later. Emits light. The LED drive control unit 32 inputs a signal indicating that the LED 21 has been driven to the signal processing unit 34. The reference pulse output from the oscillation circuit 38 is input to the read pulse generation unit 40.
[0028]
Based on the reference pulse input from the oscillation circuit 38, the read pulse generator 40 generates a pulse for sequentially switching each light receiving element of the optical sensor 25 and reading the output signal. To the unit 34. The sensor output reading unit 36 is constituted by, for example, a multiplexer or the like, and sequentially switches each light receiving element of the optical sensor 25 in synchronization with the pulse output from the reading pulse generation unit 40, and outputs the output signal to the signal processing unit. 34. On the other hand, when the LED drive signal is input from the LED drive control unit 32, the signal processing unit 34 gives a pulse command to the read pulse generation unit 40 to output the read pulse and outputs the read pulse to the read pulse generation unit 40. The output signal of the sensor output reading unit 36 is read in synchronism, and as will be described later, the diameter of the rolling tool 12 (blade diameter), the amount of deflection, the blade diameter including the deflection, and the rolling tool for the unbalanced position of the spindle The runout amount of the spindle including the runout due to the phase of the 12 blades and the shape accuracy error of the rolling tool 12 is calculated.
[0029]
The signal processing unit 34 has a binarization circuit 52 as shown in FIG. The binarization circuit 52 amplifies and binarizes the output of the sensor output reading unit 36, that is, the output of each light receiving element of the optical sensor 25. In the case of the embodiment, the binarization circuit 52 outputs an inverted output, and the output of the light receiving element that is exposed to light is “L”, and the output of the light receiving element that is in the shadow 27 that is not exposed to light Is output as “H”.
[0030]
The signal processing unit 34 is provided with a first edge point detection circuit 54 and a second edge point detection circuit 56 that constitute a projection position detection unit 53 on the output side of the binarization circuit 52. In the case of the embodiment, the first edge point detection circuit 54 is a light receiving element (first edge point E) which is the uppermost shadow of the optical sensor 25 shown in FIG.₁) Is detected. Further, the second edge point detection circuit 56 becomes a shadow on the lowermost side of the optical sensor 25 and receives the light receiving element (second edge point E₂) Is detected. The output of the first edge point detection circuit 54 and the output of the second edge point detection circuit 56 are input to a tool width calculation circuit 58 that forms part of the variation detection unit 57. The tool width obtained by the tool width calculation circuit 58 is input to the maximum width hold circuit 60. The maximum width hold circuit 60 stores and holds the maximum value obtained by the tool width calculation circuit 58 and outputs it as the diameter (blade diameter) of the turning tool 12.
[0031]
The output of the first edge point detection circuit 54 is input to the minimum value hold circuit 62 that constitutes the fluctuation detection unit 57, and the first edge point E₁, The position of the light receiving element that is the uppermost side of the optical sensor 25 in FIG. 1 is stored and held by the minimum value holding circuit 62. Further, the output of the second edge point detection circuit 56 is input to the maximum value hold circuit 64 and the second edge point E₂1 is detected and multiple times, the position of the light receiving element that is the lowest side in FIG. 1 of the optical sensor 25 is stored and held by the maximum value hold circuit 64.
[0032]
On the output side of the minimum value hold circuit 62 and the maximum value hold circuit 64, an amplitude calculation circuit 66 is connected. The runout width calculation circuit 66 calculates and outputs the maximum blade diameter (diameter) including runout of the rolling tool 12 based on the values held by the minimum value hold circuit 62 and the maximum value hold circuit 64. . Then, the value obtained by the shake width calculation circuit 66 is input to a shake amount calculation circuit 68 provided on the output side of the shake width calculation circuit 66. The runout amount calculation circuit 68 rotates from the maximum width which is the blade diameter of the rolling tool 12 stored and held in the maximum width hold circuit 60 and the maximum blade diameter including the runout obtained by the runout width calculation circuit 66. The amount of deflection of the turning tool 12 is calculated and output.
[0033]
The operation of the shake measuring apparatus 10 according to this embodiment is as follows. A turning tool 12 such as a drill or an end mill is mounted on a chuck of a spindle (not shown) and is rotated at a predetermined rotation speed. Then, the cutting tool 12 is moved in the axial direction by the feed control device 14, and is arranged at a predetermined measurement position in a state where the tip portion is rotated. That is, the tip of the cutting tool 12 is inserted into the optical path of the parallel light 26 at a position corresponding to the optical sensor 25. The position of the tip of the rolling tool 12 is detected by a position sensor (not shown) and is input to the feed control device 14. The feed control device 14 stops the feed of the cutting tool 12 in response to the input of the tip position detection signal from the position sensor. Then, the control / calculation unit 30 activates the measurement program in response to a signal from the feed control device 14.
[0034]
FIG. 3 is a flowchart illustrating the operation of the control / calculation unit 30 according to the embodiment. In the control / calculation unit 30, when the shake amount measurement program is activated, first, the signal processing unit 34 gives the LED drive control unit 32 a command to drive the LED 21. Then, the LED drive control unit 32 generates a pulse for driving the LED 21 based on the reference pulse output from the oscillation circuit 38, and drives the LED 21 to emit pulsed light. The radiation time of the pulsed light by the LED 21 is set so that the amount of movement in the circumferential direction of the tip of the cutting tool outer peripheral blade during the radiation time is less than the measurement resolution. Further, the LED drive control unit 32 inputs a drive signal for the LED 21 to the signal processing unit 34.
[0035]
The pulsed light emitted from the LED 21 is converted into parallel light 26 by the collimator lens 22, and then irradiated to the rolling tool 12 from the side perpendicular to the axial direction thereof and enters the imaging lens 24. The imaging lens 24 enlarges and projects the shadow 27 of the turning tool 12 on the optical sensor 25.
[0036]
On the other hand, when the LED drive signal is input from the LED drive control unit 32, the signal processing unit 34 of the control / calculation unit 30 gives a pulse output command to the read pulse generation unit 40. The read pulse generation unit 40 takes in the reference pulse output from the oscillation circuit 38 to generate a read pulse, and inputs it to the sensor output read unit 36 and the signal processing unit 34. Then, when the reading pulse is input from the reading pulse generation unit 40, the sensor output reading unit 36 sequentially switches each light receiving element constituting the optical sensor 25 from the upper side of FIG. 1 and reads the output signal. , Input to the signal processing unit 34. The read pulse generation unit 40 generates a read pulse so as to obtain output signals of all the light receiving elements constituting the optical sensor 25 and supplies the read pulse to the sensor output read unit 36.
[0037]
The signal processing unit 34 sequentially reads the output of the sensor output reading unit 36, that is, the output signal of the light receiving element in synchronization with the pulse output from the reading pulse generation unit 40 by the binarization circuit 52, and binarizes the first edge. This is input to the point detection circuit 54 and the second edge point detection circuit 56. The binarization circuit 52 amplifies the output signal of the light receiving element, binarizes it, and outputs it. When the output signal of the light receiving element receiving light is input, it outputs “L” and milling. When an output signal of a light receiving element that is located in the projected shadow 27 of the tool 12 and does not receive light is input, “H” is output (step 81 in FIG. 3).
[0038]
The first edge point detection circuit 54 of the signal processing unit 34 sequentially reads the output signal of the binarization circuit 52 and the light receiving element when the output signal of the binarization circuit 52 changes from “L” to “H”. Position, first edge point E₁Is sent to the tool width calculation circuit 58 and the minimum value hold circuit 62. The minimum value hold circuit 62 has a value E₁Is stored and held (step 82).
[0039]
On the other hand, the second edge point detection circuit 56 sequentially reads the output signal of the binarization circuit 52 and outputs the “L” when the output signal of the binarization circuit 52 changes from “H” to “L”. The position of the light receiving element immediately before the output light receiving element, the second edge point E₂And its value E₂Is output to the tool width calculation circuit 58 and the maximum value hold circuit 64. The maximum value hold circuit 64 outputs the value E output from the second edge point detection circuit 56.₂Is stored and held (step 82).
[0040]
The tool width calculation circuit 58 calculates the E obtained by the first edge point detection circuit 54.₁E obtained by the second edge point detection circuit 56₂And based on
[Expression 1]

And the obtained D is sent to the maximum width hold circuit 60 as the tool width of the rolling tool 12. The maximum width hold circuit 60 stores and holds the tool width obtained by the tool width calculation circuit 58 (step 83).
[0041]
Thereafter, the signal processing unit 34 of the control / calculation unit 30 determines whether or not the LED drive control unit 32 lights the LED 21 for a preset number of times (step 84). If the LED 21 has not been driven a predetermined number of times, the signal processing unit 34 proceeds to step 85, determines whether or not the LED 21 has been driven, and waits for the drive time if the LED 21 has not been driven. . When the signal processing unit 34 determines that the driving time of the LED 21 is reached, the signal processing unit 34 returns to step 81 to give an instruction to drive the LED 21 to the LED driving control unit 32, and turns on the LED 21 to emit parallel light 26 to the rolling tool 12. , And the processing from step 81 to step 84 is performed.
[0042]
In the case of this embodiment, the driving interval of the LED 21, that is, the time from when the LED 21 is lit until the next lighting is made different from each other. For example, if the LED drive control unit 32 performs the second drive 1000 pulses after completing the first LED 21 drive (lighting), the third drive is 1005 after the second drive is completed. Similarly, the LED 21 drive interval is varied, such as driving after the pulse, and driving the fourth time after 1010 pulses after the completion of the third drive. This is because when the LED 21 is lit at a constant interval, the lighting cycle of the LED 21 and the rotation cycle of the rolling tool 12 are synchronized, and it is avoided to always measure the same rotation phase. Therefore, by changing the lighting cycle of the LED 21 and detecting a plurality of times, the phase of the measured turning tool 12 differs for each measurement, and the true blade diameter of the turning tool 12 can be obtained reliably. In addition, in the embodiment, the rolling tool 12 is irradiated with pulsed light to detect the instantaneous position of the shadow 27 of the rolling tool 12 and to detect a plurality of times at appropriate intervals. Twelve moments, the position of the moment can be obtained accurately, and an accurate value of the shake amount can be obtained.
[0043]
The first edge point E obtained by the first edge point detection circuit 54 in the measurement synchronized with the light emission of the LED 21 from the second time onward.₁Is smaller than the previously obtained value, the minimum value hold circuit 62 replaces the value stored and held so far with E newly input from the first edge point detection circuit 54.₁The value of is stored. E newly obtained by the first edge point detection circuit 54₁Has been held by the minimum value hold circuit 62 until now.₁If the value is equal to or larger than the minimum value, the minimum value hold circuit 62 stores and holds E.₁Do not update the value of. Further, the maximum value hold circuit 64 is an E newly obtained by the second edge point detection circuit 56.₂Is greater than the value held so far, it is updated and stored, and the second edge point detection circuit 56 newly determines E₂The value of E previously obtained₂If the value is equal to or less than the value, the value already stored and held continues to be stored and held as it is.
[0044]
On the other hand, in the second and subsequent measurements, the tool width calculation circuit 58 uses the first edge point E obtained by the first edge point detection circuit 54 and the second edge point detection circuit 56.₁And second edge point E₂And from
[Expression 2]

And the obtained value of D is sent to the maximum width hold circuit 60. The maximum width hold circuit 60 updates and stores the newly input tool width D when the value of the newly input tool width D is larger than the value stored and held, and the newly input D value is less than the value stored and held. In some cases, the previous value is stored and held as it is.
[0045]
When the signal processing unit 34 determines that the number of times of driving and lighting of the LED 21 by the LED control driving unit 32 has reached a predetermined value in Step 84 of FIG. 3, the control / calculation unit 30 proceeds to Step 86 and proceeds to the turning tool 12. The blade diameter and runout are output. That is, the maximum width hold circuit 60 of the signal processing unit 34 stores and holds D (D_MAX) As a blade diameter (diameter) of the rolling tool 12 to a display device or the like. In addition, the fluctuation calculation circuit 66 of the signal processing unit 34 has an E stored and held in the minimum value hold circuit 62.₁Minimum value E_1MINE stored in the maximum value hold circuit 64₂Maximum value E_2MAX, And the blade diameter D ′ including runout which is a kind of runout component of the rolling tool 12,
[Equation 3]

Is calculated and output to a display device or the like.
[0046]
Further, the value of D ′ obtained by the swing width calculation circuit 66 is the value of D output from the maximum width hold circuit 60._MAXAt the same time, it is input to the shake amount calculation circuit 68. The runout amount calculation circuit 68 receives the input blade diameter D._MAXAnd the blade diameter D ′ including the deflection, the deflection amount 2B, which is the deflection component of the rolling tool 12 due to the spindle deflection, from which the blade diameter dimension of the rolling tool 12 is removed, is calculated by the following equation, and the display device or the like Output to.
[Expression 4]

[0047]
As described above, in the embodiment, since the turning amount 2B of the turning tool in the rotation state in which the turning tool 12 is actually used can be obtained, the change with time of the turning amount can be observed, The quality of the spindle, the quality of the chuck, and the like can be determined by comparing the magnitude of the amount of vibration. In the embodiment, since the blade diameter D ′ including the deflection of the turning tool at the rotational speed actually used by the turning tool is obtained, correction is performed based on the blade diameter D ′. By providing the machine tool, the machining accuracy can be improved.
[0048]
By the way, the inventors have conducted researches and conducted various experiments in order to improve machining accuracy, and in the case of a rolling tool, particularly a rolling tool in which the cutting edge is formed in a spiral shape, the spindle has runout. When present, a phenomenon has been found in which the amount of rotational runout periodically changes in the direction along the axis of the rolling tool 12. Therefore, in this embodiment, a change in axial deflection with respect to the rolling tool 12 is also measured. Therefore, D is the blade diameter output by the maximum width hold circuit 60._MAXThe value of the blade diameter D ′ including the runout of the rolling tool 12 output from the runout width calculation circuit 66 and the value of the runout 2B obtained by the runout amount calculation circuit 68 are stored in the storage unit (not shown) in the axis of the rolling tool 12. It is stored corresponding to the direction position (step 86 in FIG. 3). Then, the signal processing unit 34 of the control / calculation unit 34 determines whether or not the measurement has been completed for all the measurement ranges set in advance in the axial direction of the rolling tool 12 (step 87).
[0049]
If the measurement for the entire measurement range has not been completed, the signal processing unit 34 of the control / calculation unit 30 outputs a feed command to the feed control device 14 (step 88) and returns to step 80. The feed control device 14 moves the rolling tool 12 by a predetermined amount in the axial direction based on a command from the control / calculation unit 30. And the signal processing part 34 will repeat the process of step 80-step 87, if the signal to the effect of having moved the rolling tool 12 by the predetermined amount (for example, 0.1 mm) to the axial direction from the feed control apparatus 14 is input. When the signal processing unit 34 finishes measuring the deflection for the entire measurement range in step 87, the maximum deflection amount 2B when measured by moving the rolling tool 12 in the axial direction in step 89._MAXAnd the maximum value D ′ of the cutting tool diameter including the runout_MAXEtc. are output.
[0050]
FIG. 9 shows an outline of the processing for obtaining the fluctuation amount of the deflection amount in the axial direction of the rolling tool 12 by the signal processing unit 34. When the rolling tool 12 is fed in the axial direction by a predetermined amount by the feed control unit 14, the signal processing unit 34 measures each measurement position Z (Z in the axial direction of the rolling tool 12.₁~ Z_n) And the blade diameter D as described above_MAX(D_MAX1~ D_MAXn) And blade diameter D '(D'₁~ D '_n) And ask. The blade diameter D ′ including run-out is output together with the measurement position information Z, is used for the calculation of the run-out amount 2B, and obtains a function representing the fluctuation of the run-out amount in the phase detection unit in the axial direction of the rolling tool. Served for. Also, the blade diameter D does not include runout_MAXIs used for the calculation of the amount of deflection and the calculation of the function representing the fluctuation thereof together with the blade diameter D ′ including the deflection.
[0051]
The calculation of the runout 2B is performed for each measurement at each measurement point Z in the axial direction of the rolling tool 12. For example, when the cutting tool 12 has two blades, the calculation of the deflection amount 2B is D′−D as described above._MAXSought by. Then, the obtained runout amount 2B is held at the maximum value, and when the runout amount is measured over one cycle or more of runout fluctuation in the axial direction of the rolling tool 12, the maximum value 2B is obtained._MAXIs a spindle run-out amount (hereinafter simply referred to as spindle run-out amount) R including run-out due to accuracy error of the rolling tool 12 and shape errors such as tool holder and collet.₀Is output as Also, the spindle runout R₀Cutting edge diameter D '_MAX(D_MAX+ R₀) Is requested and output.
[0052]
On the other hand, when the length of the rolling tool 12 is shorter than one cycle of the twist of the blade as in an end mill, the signal processing unit 34 outputs the maximum value of the measured deflection amount 2B in the axial length of the rolling tool. , The maximum value D ′ (= D_MAX+ 2B) is output.
[0053]
According to the research by the inventors, the fluctuation of the runout in the axial direction of the rolling tool 12 and the fluctuation of the blade diameter D ′ including the runout are sinusoidal. The period of the fluctuation amount can be expressed as a function of the blade diameter D, the twist angle θ of the cutting blade, and the number N of blades. For this reason, in order to obtain a function representing the fluctuation of runout, the twist angle θ of the blade and the number N of blades are given in advance.
[0054]
The calculation of the function is performed by measuring the measurement position Z in the axial direction of the cutting tool 12 and the blade diameter D corresponding to the measurement position Z._MAXAnd a function approximation of D ′ using the blade diameter D ′ including runout, the twist angle of the blade given in advance, and the number of blades,
[Equation 5]

As required. Further, in this function calculation, a runout period T (one cycle of runout fluctuation in the tool axis direction) is obtained. The period T of fluctuation of the runout is a function of these, assuming that the blade diameter is D, the twist angle of the blade is θ, and the number of blades is N,
[Formula 6]

It can be expressed as.
[0055]
The function indicating the fluctuation of the blade diameter D ′ including the runout and the period T obtained in this way is the maximum runout (spindle runout R₀) And the phase α of the blade along the axial direction of the rolling tool 12 with respect to the unbalanced position of the spindle.
[0056]
That is, according to studies by the inventors, when the spindle has runout, there is a certain relationship between the tool blade phase α with respect to the unbalanced position of the spindle and the runout amount of the tool. For example, in the case of the tip position of the rolling tool 12, if the phase α of the blade at the tip of the rolling tool 12 is 0 degree with respect to the unbalanced position of the spindle, the deflection of the tip of the rolling tool 12 is The amount is maximized. That is, the antinode portion of the runout that changes in a sine wave shape along the axial direction of the cutting tool is the cutting edge position of the tool. On the other hand, when the phase α of the blade at the tip of the tool with respect to the unbalanced position of the spindle is 90 degrees, the portion of the knot amount that varies in a sine wave form becomes the tip position of the rolling tool 12 and hardly swings. The same applies to the relationship of the blade phase in the axial direction of the rolling tool 12 with respect to the unbalanced position of the spindle.
[0057]
Therefore, even when the length of the milling tool 12 that can be measured does not have a length of one or more cycles of the twist of the blade, the blade diameter D ′ including the runout obtained as described above can be obtained. The spindle runout amount R, which is the maximum runout of the rolling tool 12, by the function indicating the fluctuation and the period T of the function in the tool axis direction.₀And the amount of deflection of the tip of the rolling tool 12 can be obtained. If the amount of deflection at the tip of the rolling tool 12 is obtained, the amount of deflection R of the spindle of this amount of tip deflection is determined.₀From this ratio, the phase α of the blade at the tip of the rolling tool 12 with respect to the unbalanced position of the spindle can be obtained, and how the phase of the blade with respect to the unbalanced position of the spindle along the tool axis direction is also obtained. The unbalanced position of the spindle can be easily obtained from the mounted state of the rolling tool 12.
[0058]
As described above, in the embodiment, since the fluctuation in the axial direction of the rolling tool 12 at the rotational speed at which the rolling tool 12 is actually used and the fluctuation in the blade diameter including the fluctuation can be obtained, the rolling tool The actual runout amount during use of 12 and the blade diameter including the actual runout are obtained, and by performing correction based on this, the machining accuracy can be improved. In addition, since the phase of the blade at the tip of the tool with respect to the unbalanced position of the spindle can be determined, for example, when only the tip of the turning tool is used, for example, when machining a die by a ball end mill, the spindle is unbalanced. Determine the phase of the cutting tool tip relative to the balance position, and reduce the turning tool tip deflection by rotating the tool and re-chucking when the turning tool deflection is large As a result, the processing accuracy can be increased.
[0059]
In the embodiment, since the tool width D is obtained in the axial direction of the cutting tool 12, the variation in the blade diameter based on the machining error of the turning tool 12, that is, the machining accuracy of the turning tool 12 is also obtained. be able to.
[0060]
FIG. 4 schematically shows the deflection amount measured by moving the two-blade rolling tool 12 in the axial direction. As shown in FIG. 4, the runout of the rolling tool 12 changes substantially sinusoidally along the axis of the rolling tool, as indicated by the broken line. Further, depending on the mounting state of the turning tool on the chuck, as shown in FIGS. 1A and 1B, the deflection at the tip of the turning tool 12 may be minimized. As described above, this is due to the phase of the blade at the tip of the rolling tool 12 with respect to the unbalanced position of the spindle. As shown in FIG. 4 (1), when the amount of run-out variation occurs at the tip of the rolling tool 12, the tip blade phase with respect to the unbalanced position of the spindle is 90 degrees. As shown in FIG. 2B, the fluctuation of the deflection at the tip of the rolling tool 12 is maximum when the phase of the blade at the tip of the tool with respect to the unbalanced position of the spindle is 0 degree. It should be noted that the period T of the change in the runout amount is, according to the analysis by the inventors, where D is the blade diameter of the rolling tool 12, θ is the twist angle of the cutting blade, and N is the number of blades.
[Expression 7]

It can be expressed as.
[0061]
As described above, in the embodiment, since the rolling tool 12 is moved in the axial direction and the deflection amount is obtained at a plurality of locations in the axial direction, the maximum value of the deflection amount due to the rotation of the rolling tool 12, that is, The true runout amount and the maximum value of the blade diameter including the runout can be reliably obtained. Therefore, the machining accuracy can be improved by performing a cutting process considering these values.
[0062]
By the way, the edge point E with respect to an arbitrary reference point₁Or edge point E₂By obtaining one of these, it is possible to obtain not only the even number of blades but also the odd-numbered cutting tool 12, such as the amount of runout and the one-side position of the blade diameter including the runout. That is, as shown in FIG. 5, a reference point, for example, the upper end of the optical sensor 25 of FIG.₁) Is determined as described above while moving the rolling tool 12 in the axial direction. And the maximum value x of the obtained x_MAXAnd the minimum value x_MINFrom the difference, the amount of deflection on one side in the radial direction with respect to the center of the rolling tool 12 can be calculated.
[0063]
As a result, a value corresponding to half of the value of 2B measured by detecting both end positions of the shadow 27, that is, the deflection amount B on one side with respect to the center of the rolling tool 12 is x._MAX-X_MINAs a result, the overall shake amount 2B can be obtained by doubling this. Further, in the method for obtaining the positions of both ends of the shadow 27 described above, even when the number of blades that could not be obtained is an odd number, as described later, the shake amount 2B can be obtained.
[0064]
Also in the method of obtaining the runout 2B by detecting only the position of one side of the shadow 27, the rolling tool with respect to the fluctuation of the runout 12 in the axial direction, the runout of the spindle, and the unbalanced position of the spindle. The blade phase can be obtained. FIG. 10 is a diagram for explaining the outline of processing for detecting the fluctuation of the axial shake by detecting the position of one side of the shadow 27 projected on the optical sensor 25. In this case, as shown in FIG. 2, the position of one side of the shadow 27 (the first edge point E₁) Is output as e.
[0065]
That is, the signal processing unit 34 corresponds to each measurement position Z in the axial direction of the rolling tool 12 and information e (e₁~ E_n) The obtained value e is the maximum value e in the maximum value hold circuit and the minimum value hold circuit._MAXAnd the minimum value e_MINAnd are selected. This e_MAXAnd e_MINMeans x in the description of FIG._MAXAnd x_MINIt corresponds to.
[0066]
Next, the signal processing unit 34 determines the deviation g between the maximum value and the minimum value._N(= E_MAX-E_MIN) Is obtained (see FIG. 6 (4)). Deviation g obtained in this way_NWhen the measuring range in the axial direction of the rolling tool 12 is shorter than one cycle of the twist of the blade, it is output as a fluctuation value of the deflection amount in the measuring range. Further, when the measurement range is one cycle or more of the twisting of the cutting tool blade, the runout amount R of the spindle using a predetermined number N of blades.₀Is obtained by the following equation.
[Equation 8]

Where k_NIs a constant determined by the number N of blades. According to inventors' research,
[Equation 9]

As required. In Equation 9, N is the number of blades, and N ≧ 2. However, in the case of a single blade (N = 1), N = 2.
[0067]
Further, the signal processing unit 34 is given a function e = f representing the state of variation in the axial direction of the rolling tool 12 by function approximation based on variation of e given the twist angle of the blade and the number of blades in the same manner as described above. (Z) and its period T are obtained. Then, as described above, the spindle runout R₀And the phase α of the blade at each point along the axial direction of the tool with respect to the unbalanced position of the spindle.
[0068]
When the turning tool 12 is moved along the axial direction and the runout amount is measured, the pattern of the change in the axial direction of the runout differs depending on the number of cutting edges. FIG. 6 schematically shows the state. FIG. 1 (1) shows a change in the axial direction of runout of a single blade, and FIG. 2 (2) shows a case of two blades each having a cutting blade in the diameter direction. In either case, the height of the peak of the curve that changes sinusoidally can be regarded as the actual amount of deflection on one side in the usage state of the rolling tool 12, and one side of the spindle including the deflection due to tool shape accuracy error. Runout (R₀/ 2 = B). Therefore, the blade diameter D ′ including runout is a value obtained by adding 2B to the blade diameter D of the rolling tool 12 (D + 2B).
[0069]
FIG. 6 (3) schematically shows a change in runout in the axial direction of a rolling tool having four cutting edges at 90 degree intervals with respect to the center. In the case of this four-blade, as shown on the left side of FIG. 6 (3), a broken line is drawn between the peak of the amount of vibration caused by the first blade and the peak of the amount of vibration caused by the third blade shown by the solid line. The peak of the run-out amount by the second blade shown appears, and the peak by the fourth blade comes between the peak by the third blade and the peak by the first blade. For this reason, the change in the axial direction of the shake amount actually measured is as shown on the right side of FIG.
[0070]
FIG. 4 (4) shows a change in runout in the axial direction of a rolling tool having three cutting edges at intervals of 120 degrees with respect to the center. Also in this case, as in the case of the 4-blade, since the change in the shake amount due to each blade overlaps as shown on the left side of FIG. 6 (4), the actual measured shake amount is in the axial direction. The change along is as shown on the right side of FIG.
[0071]
As shown in FIGS. 6 (3) and 6 (4), in the case of four blades or three blades, as shown in FIG. 5, the amount of shake cannot be obtained only by detecting the position of one side of the shadow. However, since the change in the axial direction of the shake amount by each blade changes in a sine wave shape, as described above, the shake amount can be easily obtained if the twist angle of the cutting blade and the number of blades are known.
[0072]
In addition, the said embodiment is description of 1 aspect of this invention, Comprising: It is not limited to this. For example, in the above-described embodiment, when the change in axial runout is obtained, the rolling tool 12 is fed by a predetermined amount in the axial direction, and the runout is obtained in a state where the feed is stopped. The movement of the tool 12 in the axial direction may be performed slowly and continuously, the deflection may be measured while moving the rolling tool 12, and the maximum value may be set as the actual deflection amount. That is, for example, when the rolling tool 12 has two blades, the value x shown in FIG. 5 is obtained while moving the rolling tool 12 in the axial direction, and the deflection obtained from the obtained maximum and minimum values of x is obtained. The amount may be doubled to obtain the actual shake amount. When the number of blades is an even number, the first edge point E₁And second edge point E₂Also when the runout amount is obtained from the first edge point E while moving the rolling tool 12 in the axial direction.₁And the second edge point E₂By obtaining the maximum value of, the shake amount can be obtained in the same manner.
[0073]
Further, in the above embodiment, the case where the turning tool 12 is moved in the axial direction when the fluctuation amount of the turning amount in the axial direction of the turning tool 12 is obtained has been described. However, the optical sensor 25 side is moved. May be. Moreover, in the said embodiment, although the case where a light source was LED21 was demonstrated, a laser diode etc. may be sufficient as a light source.
[0074]
Furthermore, in the said embodiment, although the pulse-shaped light was irradiated to the cutting tool 12 with LED21, the light receiving element of the optical sensor 25 was switched sequentially, and the case where the output signal of a light receiving element was read was demonstrated. In addition, a buffer is provided corresponding to each light receiving element of the optical sensor 25, and an output of each light receiving element is simultaneously read into the corresponding buffer at an arbitrary timing, and a shake is obtained based on this. It may be.
[0075]
7 and 8 show the results of actual measurement of the rotational runout of the turning tool by the runout measurement apparatus 10 according to the example.
FIG. 7 shows the state of change of the blade diameter D ′ including runout in the axial direction with respect to the end mill. The horizontal axis indicates the movement distance (axial movement amount) in the rotation axis direction of the end mill in mm. Yes, the vertical axis indicates the end mill blade diameter (diameter) in mm. The used end mill has two blades having an outer diameter (blade diameter) of 0.990 mm, and the twist angle of the cutting blade is 30 degrees. The rotational speed of the end mill is 2000 rpm. Further, the solid curve in the figure is a value obtained by analysis under the same conditions, and ■ indicates an actual measurement value of the blade diameter including runout, that is, a value obtained by output from the runout calculation circuit 66 shown in FIG. is there. Further, the broken line in FIG. 7 is an actually measured value of the outer diameter of the end mill, that is, a value based on the output of the maximum width hold circuit 60 shown in FIG.
[0076]
As shown in FIG. 7, it can be seen that the blade diameter including runout, that is, the runout amount changes along the axis of the end mill. The maximum amount of spindle deflection obtained from FIG. 7 was about 10 μm (1.000 to 0.990 = 0.01 [mm]).
[0077]
FIG. 8 shows the state of change of the blade diameter including runout in the axial direction of the two-blade drill. The horizontal axis is the movement distance (unit: mm) in the rotation axis direction of the drill, and the vertical axis is Blade diameter (unit: mm). The used drill has an outer diameter of 0.403 mm, a twist angle of the cutting edge of 30 degrees, and a rotational speed of the drill of 12000 rpm. In the figure, the solid line is a value obtained by simulation, ■ is the measured value of the blade diameter including runout, and the broken line is the measured value of the drill's blade diameter.
[0078]
As shown in FIG. 8, the blade diameter (runout amount) including runout changes in the axial direction also in the drill. In addition, the blade diameter (runout amount) including runout periodically changes in the axial direction.
[0079]
FIG. 11 shows the relationship between the phase of the cutting edge at the tip of the rolling tool 12 with respect to the unbalanced position of the spindle and the blade diameter including the runout (runout amount). The distance (unit: mm), and the vertical axis is the blade diameter (unit: mm). In addition, the curve indicated by the broken line in the figure shows the analysis value when the phase of the blade at the tip of the tool with respect to the unbalanced position of the spindle is 0 degrees, the two-dot chain line is the same when the phase is 45 degrees, and the solid line is the phase. The case of 90 degrees is shown. In the figure, ▲ is an actually measured value when the phase is 0 degree, x is an actually measured value when the phase is 45 degrees, and ● is an actually measured value when the phase is 90 degrees.
[0080]
As is apparent from the figure, in the case of a two-blade rolling tool, the deflection at the tip of the cutting tool is maximized when the phase of the blade at the tip of the tool with respect to the unbalanced position of the spindle is 0 degrees, and the phase is 90. Minimum when in degrees. And when the phase is 45 degrees, it is in between.
[0081]
In this way, if there is runout in the spindle, the runout of the rolling tool 12 periodically varies in the axial direction, and there is a constant amount between the blade phase of the milling tool 12 and the runout amount with respect to the unbalanced position of the spindle. A relationship exists. For this reason, for example, when side cutting is performed by an end mill, the run-off pattern of the end mill is transferred to the processed cutting surface. So, for example, adjust the blade phase so that the deflection at the end of the end mill is maximized, and attach it to the chuck. By slightly shifting in the axial direction and cutting again so as to cut the convex portion transferred from the end mill to the cutting surface, by repeating this cutting process multiple times, the machined cutting surface is flattened and the processing accuracy is improved. Can be improved.
[0082]
【The invention's effect】
As described above, according to the present invention, the rotating tool is irradiated with light to project the shadow of the turning tool onto the optical sensor, and the positions of both ends of the shadow are obtained. By determining the positions of both ends of this shadow at a plurality of positions along the axial direction of the rolling tool, the fluctuations in the axial direction of the rolling tool can be obtained with respect to the positions of both ends of the shadow in the direction perpendicular to the axis of the rotating rolling tool. Is obtained. Therefore, based on the fluctuation of the projected position of the shadow obtained along the axis of the turning tool, the cutting tool's blade diameter (diameter), the actual amount of turning of the turning tool, and the turning tool's runout were included. The actual blade diameter can be determined. For this reason, since the amount of runout along the axis of the turning tool at the actual rotational speed and the blade diameter including the runout are obtained, the actual amount of runout of the rolling tool at the actual rotational speed is obtained. The amount of run-out can be used as a reference during machining. When the run-out amount is large, the machining accuracy can be increased by exchanging the rolling tool or performing maintenance or exchange of the spindle. Further, it is possible to determine the quality of the chuck by grasping the chuck that constantly generates a large rotational runout, and it is possible to determine the quality in a state where the spindle and the chuck are combined. Furthermore, since the actual blade diameter including the deflection of the turning tool at the actual rotation speed can be obtained, the machining accuracy can be improved by giving the machine tool correction in consideration of the blade diameter.
[0083]
In the present invention, since the shadow projection position is detected by detecting one side edge of the shadow with respect to the reference position, not only in the case of a rolling tool having an even number of cutting edges, the blade diameter Even when the number of cutting blades for which the value cannot be obtained is an odd number, the actual runout amount can be obtained accurately and reliably. Therefore, it is possible to improve the machining accuracy with the rolling tool having odd-numbered blades.
[0084]
And since the amount of run-out is determined along the axial direction of the cutting tool, the amount of run-out is compared with the maximum amount of run-out, so that the blade at each position along the axis of the turning tool relative to the unbalanced position of the spindle The phase of the tool can be easily determined, and the amount of deflection of the working position in the axial direction of the turning tool can be adjusted by adjusting the phase of the blade when mounting the turning tool on the chuck. , Machining accuracy can be improved.
[0085]
Furthermore, since the amount of runout is calculated along the axis of the turning tool, the amount of runout of the spindle, including runout due to shape accuracy error of the turning tool at the actual rotation speed, is the maximum amount of runout of the turning tool. By monitoring this spindle run-out, it can be used to determine whether the spindle is good or bad, or whether the chuck is good or bad.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a measuring device for a rolling tool according to an embodiment of the present invention.
FIG. 2 is a block diagram of a signal processing unit according to an embodiment of the present invention.
FIG. 3 is a flowchart for explaining a turning tool run-out measuring method according to the embodiment of the present invention.
FIG. 4 is an explanatory view schematically showing a change in the amount of runout in the axial direction of the cutting tool.
FIG. 5 is a view for explaining a method of measuring a runout of a rolling tool according to a second embodiment of the present invention.
FIG. 6 is a diagram for explaining a difference due to the number of blades in the change in the amount of runout in the axial direction of the turning tool.
FIG. 7 is a diagram showing changes in the blade diameter including runout in the axial direction of the end mill measured according to the embodiment.
FIG. 8 is a diagram showing changes in the blade diameter including runout in the axial direction of the drill measured according to the embodiment.
FIG. 9 is an explanatory diagram of a method for obtaining fluctuations in the axial direction of the rolling tool based on the positions of both ends of the shadow according to the embodiment.
FIG. 10 is an explanatory diagram of a method for obtaining fluctuations in the axial direction of the rolling tool based on the position of one side end of the shadow according to the embodiment.
FIG. 11 is a diagram showing the relationship between the blade phase at the tip of a two-blade tool with respect to the unbalanced position of the spindle and the blade diameter including runout of the turning tool.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ......... Turning tool measuring device, 12 ......... Turning tool, 14 ......... Feed control device, 20 ...... Detection part, 21 ......... LED, 22 ...... Collimating lens, 24 ......... Imaging lens 25... Optical sensor 30... Control / calculation unit 34 34 Signal processing unit 53 Projection position detection unit 54 First edge point detection circuit 56 ...... Second edge point detection circuit, 57... Fluctuation detection unit, 58... Tool width calculation circuit, 60... Maximum width hold circuit, 66. Calculation circuit.

Claims (3)

Irradiating light from the side of the rolling tool chucked by the processing machine and projecting the shadow of the rolling tool onto an optical sensor, and at a plurality of positions in the axial direction of the rolling tool, Based on the output signal of the optical sensor, both end positions of the projected shadow are detected, and based on the detected both end positions of the shadow, a shake component is obtained along the axial direction of the rolling tool. A method for measuring a turning tool , wherein at least one of a phase of a blade of the turning tool with respect to an unbalanced position of a spindle for rotating the turning tool and a runout amount of the spindle is obtained based on . Irradiating light from the side of the rolling tool chucked by the processing machine and projecting the shadow of the rolling tool onto an optical sensor, and at a plurality of positions in the axial direction of the rolling tool, One side end position of the projected shadow is detected based on the output signal of the optical sensor, and the runout component is obtained along the axial direction of the rolling tool based on the detected one side end position of the shadow. Further, at least one of the phase of the cutting tool blade with respect to the unbalanced position of the spindle for rotating the turning tool and the amount of runout of the spindle is obtained based on the runout component. Tool measurement method. A light source that irradiates a rotating tool that is rotated by being chucked by a processing machine with pulsed light at different time intervals;
A light sensor on which the shadow of the turning tool is projected by the light irradiated by the light source;
Based on the output signal of the photosensor, a projection position detector that detects at least one of both ends of the shadow projected on the photosensor;
A feed unit that moves the optical sensor relatively in the axial direction of the machining use area of the rolling tool ;
Based on the projection position information of the shadow output from the projection position detection unit, fluctuations in the amount of runout in the axial direction used for machining the rolling tool, fluctuations in the cutting tool blade diameter, deflection of the rolling tool A fluctuation detecting unit for obtaining at least one of fluctuations of the blade diameter including
A spindle that rotates the turning tool based on fluctuations in the amount of runout of the rolling tool obtained by the fluctuation detection unit, fluctuations in the diameter of the cutting tool or blade diameter including runout of the turning tool A phase detector for determining at least one of the phase of the cutting tool blade and the amount of runout of the spindle with respect to the unbalanced position;
A measuring device for a turning tool, comprising:

Images