JP3924438B2

JP3924438B2 - Cutting tool with sensor and manufacturing method thereof

Info

Publication number: JP3924438B2
Application number: JP2001096104A
Authority: JP
Inventors: 剛深野
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2001-03-29
Filing date: 2001-03-29
Publication date: 2007-06-06
Anticipated expiration: 2021-03-29
Also published as: JP2002292504A

Description

【０００１】
【発明の属する技術分野】
本発明は切削加工に使用する工具とその作成方法に関し、特に損耗センサを備えたセンサ付き切削工具およびその作製方法に関するものである。
【０００２】
【従来技術および発明が解決しようとする課題】
切削加工において、切削工具の逃げ面の摩耗の大きさは一般的に工具寿命の判定基準となる。そのため、切削加工中にインプロセスで速やかに逃げ面の摩耗量を推定することは、高精度加工を維持する上で大変重要である。しかし、加工中に工具の摩耗を直接観察することは作業環境上大変難しい。
【０００３】
そこで、加工を中止して工具を一旦はずして工具顕微鏡などで測定したり、あるいは加工中にインプロセスで摩耗量を知りたい場合は、工具の摩耗に付随して起こる他の現象（切削力や振動の変化など）を工作機械上等の加工点付近に設置したセンサで検出して、検出信号に何らかの信号処理を行って摩耗量を推定している。
【０００４】
しかしながら、インプロセスでは摩耗の定量的な量を求めることが困難であったり、十分な感度や信頼性が得られなかった。
【０００５】
また、切削工具の切刃縁部分の摩耗量を検知することによって、工具寿命を自動的に判定する方法も提案されている。すなわち、切削工具の摩耗量を検知して工具寿命を自己診断する方法であり、導電性のある工具に応用する方法として、絶縁層中に導体路を埋設して、その導体路が切削工程中に破断したときの信号をトリガとして限界摩耗および破断を検出するものである（特開昭６２−８８５５２号公報）。
【０００６】
また、導電性母材の表面に絶縁性の酸化アルミニウム膜をコーティングして工具を形成し、被削材と工具との間に電圧をかけ、酸化アルミニウム膜が摩耗したとき、すなわち寿命になると電流が流れることを利用した工具寿命の検知方法も提案されている（特開昭５９−８１０４３号公報）。
【０００７】
これらの方法は絶縁層の絶縁状態が非常に重要である。上記特開昭６２−８８５５２号公報に示される方法では、絶縁層としてＣＶＤ法またはＰＶＤ法で酸化アルミニウム膜を作製するものである。酸化アルミニウム膜を超硬母材やサーメット母材のような熱膨張係数が異なる母材にＣＶＤ法で成膜する場合、成膜後に酸化アルミニウム膜中に母材まで通じる微細な亀裂（クラック）が発生し、酸化アルミニウム膜の上に導電センサー膜を作製した場合、そのクラックを通じて導電性母材と導電センサー膜が短絡してしまうという問題があった。
【０００８】
また、酸化アルミニウム膜をＰＶＤ法で形成する場合、酸化アルミニウム膜中に母材まで通じるピンホールなどの欠陥ができ、そのピンホールを通じて導電性母材と導電センサー膜が短絡してしまうという問題があった。また、母材の状態により絶縁層中に導電性の未反応物が残ってしまうという問題があった。これらの問題により、安定してセンサ機能を発揮できる回路を作製することは非常に困難であった。
【０００９】
また、上記特開昭５９−８１０４３号公報に示される方法は、絶縁性の酸化アルミニウム膜を得るためには、少なくとも１０μｍ〜１００μｍの酸化アルミニウム膜が必要であることが述べられている。この理由は、酸化アルミニウム膜中に存在するごく小さなクラックやカケが存在するためと述べられている。
【００１０】
この概念を図５に示す。図５中、１は導電膜、２は絶縁層、３は導電性母材、４はクラックやピンホール等の欠陥、５は導電性粒子等の欠陥である。短絡の要因である絶縁層２に存在するクラック、ピンホール、あるいは導電性粒子等の欠陥４、５が存在すると、導電センサ回路を作製するときに、その欠陥４、５等を通じて導電性母材３と導電膜１が短絡してしまう。そのためセンサ回路が正常に機能できず、信頼性の劣るものとなっていた。
【００１１】
このようなことから、従来からセンサ付工具が種々提案されているにも拘らず、未だ実用化されていない。すなわち、少数しか必要としない実験レベルでは製作が可能であっても、切削工具として実用上使用できるものはなかった。
【００１２】
また、上記特開昭５９−８１０４３号公報のように、絶縁層に存在するクラックやカケの影響をなくすために、絶縁層の厚みを厚くすると切削性能の低下を招き、また耐欠損性の劣化の問題を招来することになる。
【００１３】
本発明はこのような問題を解決することを目的とするものである。
【００１４】
【課題を解決するための手段】
上記目的を達成するために、請求項１に係るセンサ付き切削工具では、導電性母材の表面に絶縁層を設け、その上に導電膜から成るセンサ回路を形成してなるセンサ付き切削工具において、前記絶縁層は、酸化アルミニウムからなる層を連続して２層以上積層したものから成ることを特徴とする。
【００１６】
上記センサ付き工具では、前記絶縁層のうち導電性母材側の酸化アルミニウムからなる層の厚みよりセンサ回路側の酸化アルミニウムからなる層の厚みが厚いことが望ましい。
【００１７】
また、請求項３に係るセンサ付き切削工具では、導電性母材の表面に酸化アルミニウムからなる層を連続して２層以上積層した絶縁層を設け、その上に導電膜から成るセンサ回路を形成してなるセンサ付き切削工具であって、前記絶縁層中に存在する導電性物質を前記絶縁層の厚み方向で非連続にしたことを特徴とする。
【００１８】
また、請求項４に係るセンサ付き切削工具の作製方法では、導電性母材の表面に絶縁層を設け、その上に導電膜から成るセンサ回路を形成してなるセンサ付き切削工具の作製方法において、前記導電性母材上に絶縁層を形成した後、その表面をエッチングおよび／または洗浄して更に絶縁層を形成することを特徴とする。
【００１９】
【発明の実施の形態】
以下、各請求項に係る発明の実施形態をスローアウエイ工具を例として説明する。なお、ドリル等への応用も可能である。
【００２０】
図１は請求項１に係るセンサ付き切削工具の一実施形態を示す図である。図１中、６は導電膜、７は２層目絶縁層、８は１層目絶縁層、９は導電性母材、１０は２層目絶縁層部のクラックやピンホール等の欠陥部、１１は１層目絶縁層部のクラックやピンホール等の欠陥部、１２は１層目絶縁層部の導電性粒子等の欠陥部である。
【００２１】
このセンサ付き切削工具では、連続した２層以上の絶縁層７、８を重ねる。このようにすることで、次工程の導電膜を作製するときに欠陥１１、１２中に導電膜６が侵入することを防ぎ、導電性母材９と導電性回路間で短絡しなくなり、センサ回路として正常に機能させることができる。１層目絶縁層８の作製時にできた欠陥１１や１２は２層目絶縁層７で埋めたり、覆うことができる。また２層目絶縁層７の作製時にできた欠陥１０は、導電膜６の作製時に短絡要因成分が浸入するが、１層目絶縁層８により、導電性母材９と導電膜６の短絡を阻止できる。
【００２２】
導電性母材９としては、酸化アルミニウム質焼結体、窒化珪素質焼結体、サーメット、超硬合金、立方晶窒化ホウ素質焼結体（ＣＢＮ／ＣｕｂｉｃＢｏｒｏｎＮｉｔｒｉｄｅ）、ダイヤモンド焼結体（ＰＣＤ／ＰｏｌｙｃｒｙｓｔａｌｌｉｎｅＤｉａｍｏｎｄ）、またこのような導電性母材９にＰＶＤ法および／またはＣＶＤ法で周期律表４ａ、５ａ、６ａ族元素の１種乃至２種以上の炭化物、窒化物、炭窒化物、酸化物のいずれかひとつの硬質膜（不図示）をコーティングした工具等が使用できる。
【００２３】
酸化アルミニウム質焼結体としては、ＴｉＣを２〜４０重量％、Ｆｅ、Ｎｉ、Ｃｏの酸化物のうち少なくとも１種を０．０１〜重量％、残部がＡｌ₂Ｏ₃および不可避不純物からなる酸化アルミニウム質焼結体などが使用できる。
【００２４】
窒化珪素質焼結体としては、ＡｌをＡｌ₂Ｏ₃換算で１．５〜１０モル％、Ｔｉの炭化物、窒化物、炭窒化物を３０〜８０モル％、残部が窒化珪素と希土類酸化物を窒化珪素に対して１０重量％以下、不純物的酸素をＳｉＯ₂換算で１０モル％以下の割合から成る窒化珪素質焼結体などが使用できる。
【００２５】
サーメットとしては、Ｔｉを炭化物、窒化物あるいは炭窒化物換算で５０〜８０重量％、周期律表第６ａ族元素を炭化物換算で１０〜４０重量％の割合で含有するとともに（窒素／炭素＋窒素）で表される原子比が０．４〜０．６の範囲内にある硬質相成分７０〜９０重量％と、鉄族金属から成る結合相成分１０〜３０重量％とから成るＴｉＣＮ基サーメットなどある。
【００２６】
超硬合金としては、硬質相と結合相で構成されるものなどがあり、硬質相は、炭化タングステン、または炭化タングステンの５〜１５重量％を周期律表第４ａ、５ａ、６ａ族金属の炭化物、窒化物、炭窒化物で置換したものなどからなり、結合相は、Ｃｏ等の鉄族金属を主成分とするもので、例えば全量中に５〜１５重量％の割合で含有される。
【００２７】
コーティング層（不図示）としてはＴｉの炭化物、窒化物、炭窒化物を０．１μｍから１０μｍ、Ａｌの酸化物を０．１μｍから１０μｍ、ＴｉＡｌの窒化物を０．１μｍから１０μｍなどで形成され、これら硬質膜の１種類およびまたは２種以上を上記超硬合金、サーメット、セラミックなどの母材にコーティングしたものである。
【００２８】
導電性母材９と導電膜６を絶縁する絶縁層７、８は、ＣＶＤ法、ＰＣＶＤ法、イオンプレーティング、スパッタリング、蒸着等のＰＶＤ法、めっき法などで形成される。絶縁層７、８を例えばスパッタリング法で形成する場合、Ａｒ雰囲気で行なう。成膜条件はターゲットの汚れを落とすために、プレスパッタリングを１分以上、母材のエッチングを１分以上、さらにターゲットのプレスパッタリングを１分以上行なった後、例えば酸化アルミニウムの成膜を膜厚に応じて５分から２００分の間で行なう。また、ＣＶＤ法で形成する場合、キャリアガスとしてＨ₂を用い、反応ガスとしてＣＯ₂、ＨＣｌ、ＡｌＣｌ₃を用い、成膜温度は８５０℃から１１００℃の間で行い、炉内圧力は４０ｍｂａｒ〜３００ｍｂａｒの間で行なう。またこれら絶縁層７、８の材質は、窒化アルミニウム、窒化珪素、酸化ジルコニウム、酸化チタン等の絶縁性の物質でもかまわない。
【００２９】
この方法によって多層の絶縁層７、８を作製するとよい。絶縁層７、８の総厚みは０．１〜２０μｍにすることが望ましい。絶縁層７、８を０．１μｍ以上とするのはそれ以下では絶縁効果がなくなる恐れがあるためである。また、絶縁層７、８の厚みは２０μｍ以下、好ましくは１０μｍ以下がよい。絶縁層７、８の厚みが２０μｍ以上になると切削性能（特に耐欠損性）に悪影響を及ぼすためである。
【００３０】
導電膜６はＴｉ、Ｚｒ、Ｖ、Ｎｂ、Ｔａ、Ｃｒ、Ｍｏ、Ｗ等の周期律表４ａ、５ａ、６ａ族金属、Ｃｏ、Ｎｉ、Ｆｅ等の鉄族金属、あるいはＡｌなどの金属材料やＴｉＣ、ＶＣ、ＮｂＣ、ＴａＣ、Ｃｒ₃Ｃ₂、Ｍｏ₂Ｃ、ＷＣ、Ｗ₂Ｃ、ＴｉＮ、ＶＮ、ＮｂＮ、ＴａＮ、ＣｒＮ、ＴｉＣＮ、ＶＣＮ、ＮｂＣＮ、ＴａＣＮ、ＣｒＣＮ等の周期律表４ａ、５ａ、６ａ族金属の炭化物、窒化物、炭窒化物、（Ｔｉ、Ａｌ）Ｎ等で形成される。この中でも、ＴｉＮはスローアウェイチップの母材に対する接合力が強いこと、被削材と反応せず、センサの電気抵抗値が常に所定値を示し、スローアウェイチップの摩耗度合い、欠損の発生の有無を正確に検出することができること、被削材の加工表面に反応生成物による傷が形成されるのを有効に防止できること、耐酸化性に優れ、酸化物生成によるセンサの電気抵抗値の変化がなく、スローアウェイチップの摩耗度合い、欠損の発生の有無を正確に検出することができること、等の理由から好適に使用し得る。
【００３１】
ＣＶＤ法やイオンプレーティング、スパッタリング、蒸着等のＰＶＤ法、めっき法等を採用することによってスローアウェイチップの母材のほぼ全面に所定厚みに導電性膜が被着される。その後、レーザ加工によって、導電性膜が所定パターンに加工され、導電膜６とする。
【００３２】
導電膜６は、その厚みが０．０５μｍ未満の薄いものでは、母材表面への接合が弱くなるとともにセンサの電気抵抗値が高くなり、スローアウェイチップの摩耗度合いや欠損を正確に検出するのが困難となってしまう危険性がある。また２０μｍを超得る導電性膜を形成しようとすると、形成時に導電性膜の内部に大きな応力が発生して残留し、この残留応力によって、導電膜６の母材表面への接合が弱いものとなってしまう危険性がある。
【００３３】
その後、レーザー加工等の方法で刃先のすくい面および逃げ面に刃先稜線と平行になるようにセンサ回路を形成する。センサ幅は一般的には０．０１ｍｍ〜０．５ｍｍでよいと考得るが、寿命設定により任意の幅を持たせるとよい。これにより電気絶縁性のよいセンサ回路を作製することができる。
【００３４】
また、絶縁層７、８としては、耐酸化性、耐摩耗性に優れることからは、酸化アルミニウムおよび／または酸化ジルコニウムを用いることが望ましい。
【００３５】
図２は、請求項３に係るセンサ付き切削工具の一実施形態を示す図である。図２において、１３は導電膜、１４は２層目絶縁層、１５は１層目絶縁層、１６は導電性母材、１７は２層目絶縁層部のクラックやピンホール等の欠陥部、１８は１層目絶縁層部のクラックやピンホール等の欠陥部、１９は１層目絶縁層部の導電性粒子等の欠陥部である。２層目絶縁層１４を、１層目絶縁層１５の厚さより厚くすることで、１層目絶縁層１５の作製時にできた欠陥１８をより効率的に埋めることができる。これにより導電性母材１６と導電性回路間での短絡を防ぎ、センサ回路として正常に機能することができるようになる。
【００３６】
図３は請求項４に係るセンサ付き切削工具の一実施形態を示す図である。図３において、２０は導電膜、２１は絶縁層、２２は導電性母材、２３はクラックやピンホール中に存在する導電膜物質、２４は導電性物質であり、導電性物質２３、２４が導電膜２０と導電性母材２２の間で非連続になることで、導電膜２０と導電性母材２２の間の短絡を防ぐことができる。絶縁層２１の厚み方向の導電性母材２２および／または導電膜２０からなる途中でピンホールやクラック中に存在する導電性物質２３、２４を非連続にすることが重要である。それにより、導電性母材２２と導電性回路間で短絡しなくなり、センサ回路として正常に機能することができる。
【００３７】
次に、請求項５に係るセンサ付き切削工具の作製方法を説明する。例えば図１において、２層目絶縁層７を形成する前に、エッチングや洗浄の工程を入れることで、１層目絶縁層８部のクラックやピンホール等の欠陥部１１、１２を２層目絶縁層７で塞ぎやすくする。１層目絶縁層８を成膜したときピンホールができるところをエッチングや洗浄で、ピンホール部分の表面を活性化させることで２層目以降の絶縁層７を成膜しやすくすることにより、１層目絶縁層８中のピンホール部を２層目絶縁層７で塞ぎ、導電性母材９から導電センサ回路間の短絡を防ぎ、センサ回路として正常に機能させることができる。
【００３８】
【実施例】
−実施例１−
実施例として以下のサンプル１を５個作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミックを用いた。導電性母材と導電膜を絶縁する絶縁層として、１層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置はＡｒ雰囲気の高周波スパッタリング装置でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。
【００３９】
次に２層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。その後、導電膜をＰＶＤでＴｉＮを成膜し回路を作製したところ、電気絶縁性のよいセンサ回路を作製することができた。電気絶縁性の調査は図４に示す方法で行なった。図４において、２７は導電性母材、２６は１層目絶縁層、２５は２層目絶縁層、２８はテスターである。電気抵抗の測定結果を表１に示す。
【００４０】
従来技術のサンプルとして以下のサンプル２を５個作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミック用母材を用いた。導電性母材と導電膜を絶縁する絶縁層として、スパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。導電膜をＰＶＤでＴｉＮを成膜して回路を作製したところ、電気絶縁性の悪いセンサ回路ができた。電気絶縁性の測定は図４に示す方法で行なった。電気抵抗の測定結果を表１に示す。
【００４１】
【表１】

【００４２】
−実施例２−
本発明実施例として以下のサンプル３を５個作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミック用母材を用いた。導電性母材と導電膜を絶縁する絶縁層として、１層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。次に２層目にスパッタリングで５μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を１００分行なった。その後、導電膜をＰＶＤでＴｉＮを成膜し回路を作製したところ、電気絶縁性のよいセンサ回路を作製することができた。電気絶縁性の調査は図４に示す方法で行なった。電気抵抗の測定結果を表２に示す。
【００４３】
サンプルとして以下のサンプル４を５個作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミック用母材を用いた。導電性母材と導電膜を絶縁する絶縁層として、スパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。次に２層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。導電膜をＰＶＤでＴｉＮを成膜し回路を作製したところ、電気絶縁性の悪いセンサ回路ができる。電気絶縁性の調査は図４に示す方法で行なった。電気抵抗の測定結果を表２に示す。
【００４４】
【表２】

【００４５】
−実施例３−
本発明実施例として以下のサンプルを作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミック用母材を用いた。導電性母材と導電膜を絶縁する絶縁層として、１層目にスパッタリングで１μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を２０分行なった。次に２層目にスパッタリングで５μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を１００分行なった。その後、導電膜をＰＶＤでＴｉＮを成膜し回路を作製し断面を確認したところ、図２に示すように、絶縁層中のピンホール、クラック内に存在する導電膜物質２３、導電性物質２４が絶縁層の厚み方向で非連続になっていることが確認できた。
−実施例４−
本発明実施例として以下のサンプル５を５個作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミック用母材を用いた。導電性母材と導電膜を絶縁する絶縁層として、１層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。次に２層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。その後、導電膜をＰＶＤでＴｉＮを成膜し回路を作製したところ、電気絶縁性のよいセンサ回路を作製することができた。電気絶縁性の調査は図４に示す方法で行なった。電気抵抗の測定結果を表３に示す。
【００４６】
従来技術サンプルとして以下のサンプル５を５個作製した。導電性母材としてＡｌ₂Ｏ₃−ＴｉＣ系セラミック用母材を用いた。導電性母材と導電膜を絶縁する絶縁層として、スパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気でプレスパッタリングを３分、母材のエッチングを１２分、ターゲットのプレスパッタリングを１５分、成膜を６０分行なった。次に２層目にスパッタリングで３μｍの酸化アルミニウム膜を作製した。スパッタリング装置は高周波スパッタリング装置を用いてＡｒ雰囲気で、成膜を６０分行なった。導電膜をＰＶＤでＴｉＮを成膜して回路を作製したところ、電気絶縁性の悪いセンサ回路ができる。電気絶縁性の調査は図４に示す方法で行なった。電気抵抗の測定結果を表３に示す。
【００４７】
【表３】

【００４８】
【発明の効果】
以上のように、請求項１に係るセンサ付き切削工具では、導電性回路を形成する前記絶縁層は、酸化アルミニウムからなる層を連続して２層以上積層したものから成ることから、次工程の導電膜作製時に欠陥中に導電膜が侵入することを防ぎ、導電性母材と導電性回路間で短絡しなくなり、センサ回路として正常に機能することができる。
【００５０】
また、請求項２に係るセンサ付き切削工具では、導電性母材側の酸化アルミニウムからなる層の厚みよりセンサ回路側の絶縁層の厚みを厚くすることから、絶縁層において１層目の酸化アルミニウムからなる層（導電性母材側）の厚みをなるべく薄くし、それによってできたピンホールなどの欠陥を２層目の酸化アルミニウムからなる層（導電性回路側）の厚みを厚くすることで塞ぐことができる。
これにより導電性母材と導電性回路間での短絡を防ぎ、センサ回路として正常に機能することができるようになる。
つまり、ＰＶＤ法においてピンホールなどの欠陥が存在するところには、成膜しにくいという欠点があり、また工具として使用するため厚膜化による耐欠損性能の劣化を考慮すると、絶縁層の厚みはなるべく薄い方がよい。
【００５１】
また、請求項３に係るセンサ付き切削工具では、絶縁層の厚み方向の導電性母材および／または導電膜からなる途中でピンホール、クラック中に存在する導電性物質を非連続にしたことで、導電性母材と導電性回路間で短絡しなくなり、センサ回路として正常に機能することができる。
【００５２】
また、請求項４に係るセンサ付き切削工具の作製方法では、導電性母材上に絶縁層を形成した後、その表面をエッチングおよび／または洗浄して更に絶縁層を形成する。
すなわち、ピンホールなどの欠陥は母材の汚れや残留水分などにより表面が活性化されていない箇所で発生することが知られている。
そのため１層目の絶縁層を成膜したときにピンホールができるところをエッチングや洗浄で、ピンホール部分の表面を活性化させることで２層目以降の絶縁層を成膜しやすくすることにより、ピンホール部を２層目の絶縁層で塞ぎ、導電性母材から導電センサ回路間の短絡を防ぎ、センサ回路として正常に機能することができる。
【図面の簡単な説明】
【図１】請求項１に係るセンサ付き切削工具の一実施形態を示す断面図である。
【図２】請求項３に係るセンサ付き切削工具の一実施形態を示す断面図である。
【図３】請求項４に係るセンサ付き切削工具の一実施形態を示す断面図である。
【図４】電気絶縁性の測定方法の概略を示す図である。
【図５】従来のセンサ付き切削工具を示す断面図である。
【符号の説明】
１：導電膜
２：絶縁層
３：導電性母材
４：クラックやピンホール等の欠陥
５：導電性粒子等の欠陥
６：導電膜
７：２層目絶縁層
８：１層目絶縁層
９：導電性母材
１０：２層目絶縁層部のクラックやピンホール等の欠陥部
１１：１層目絶縁層部のクラックやピンホール等の欠陥部
１２：１層目絶縁層部の導電性粒子等の欠陥部
１３：導電膜
１４：２層目絶縁層
１５：１層目絶縁層
１６：導電性母材
１７：２層目絶縁層部のクラックやピンホール等の欠陥部
１８：１層目絶縁層部のクラックやピンホール等の欠陥部
１９：１層目絶縁層部の導電性粒子等の欠陥部
２０：導電膜
２１：絶縁層
２２：導電性母材
２３：クラックやピンホール中に存在する導電膜物質
２４：導電性物質
２５：導電膜
２６：絶縁層
２７：導電性母材
２８：テスター[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tool used for cutting and a method for producing the same, and more particularly to a sensor-equipped cutting tool equipped with a wear sensor and a method for producing the same.
[0002]
[Background Art and Problems to be Solved by the Invention]
In cutting, the magnitude of wear on the flank of a cutting tool is generally a criterion for determining tool life. For this reason, it is very important to estimate the amount of wear on the flank quickly in-process during cutting in order to maintain high-precision machining. However, it is very difficult in the working environment to directly observe tool wear during machining.
[0003]
Therefore, if you want to stop machining and take off the tool once and measure it with a tool microscope, or if you want to know the amount of wear in-process during machining, other phenomena (cutting force and A change in vibration or the like) is detected by a sensor installed near a machining point on a machine tool or the like, and some signal processing is performed on the detection signal to estimate the wear amount.
[0004]
However, it is difficult to obtain a quantitative amount of wear by in-process, and sufficient sensitivity and reliability cannot be obtained.
[0005]
There has also been proposed a method for automatically determining the tool life by detecting the wear amount of the cutting edge portion of the cutting tool. That is, it is a method of self-diagnosis of the tool life by detecting the wear amount of the cutting tool. As a method of applying to a conductive tool, a conductor path is embedded in an insulating layer, and the conductor path is in the cutting process. The limit wear and breakage are detected using a signal when the breakage occurs as a trigger (Japanese Patent Laid-Open No. 62-88552).
[0006]
In addition, an insulating aluminum oxide film is coated on the surface of the conductive base material to form a tool, and a voltage is applied between the work material and the tool. A method for detecting the tool life using the flow of the gas is also proposed (Japanese Patent Laid-Open No. 59-81043).
[0007]
In these methods, the insulating state of the insulating layer is very important. In the method disclosed in JP-A-62-88552, an aluminum oxide film is formed as an insulating layer by a CVD method or a PVD method. When an aluminum oxide film is formed on a base material having a different thermal expansion coefficient such as a cemented carbide base material or a cermet base material by a CVD method, a minute crack (crack) leading to the base material in the aluminum oxide film after film formation When the conductive sensor film is formed on the aluminum oxide film, the conductive base material and the conductive sensor film are short-circuited through the crack.
[0008]
In addition, when the aluminum oxide film is formed by the PVD method, a defect such as a pinhole leading to the base material is formed in the aluminum oxide film, and the conductive base material and the conductive sensor film are short-circuited through the pinhole. there were. Further, there is a problem that conductive unreacted substances remain in the insulating layer depending on the state of the base material. Due to these problems, it has been very difficult to produce a circuit that can stably exhibit the sensor function.
[0009]
Further, it is stated that the method disclosed in the above Japanese Patent Application Laid-Open No. 59-81043 requires an aluminum oxide film of at least 10 μm to 100 μm in order to obtain an insulating aluminum oxide film. The reason for this is stated to be that there are very small cracks and chips present in the aluminum oxide film.
[0010]
This concept is illustrated in FIG. In FIG. 5, 1 is a conductive film, 2 is an insulating layer, 3 is a conductive base material, 4 is a defect such as a crack or a pinhole, and 5 is a defect such as a conductive particle. If there are

defects

4, 5 such as cracks, pinholes, or conductive particles present in the insulating layer 2 that are the cause of a short circuit, when the conductive sensor circuit is manufactured, the conductive base material is passed through the

defects

4, 5 and the like. 3 and the conductive film 1 are short-circuited. For this reason, the sensor circuit cannot function normally and has poor reliability.
[0011]
For this reason, although various sensor-equipped tools have been proposed, they have not been put into practical use yet. In other words, even if it was possible to manufacture at an experimental level where only a few were required, there was no tool that could be used practically as a cutting tool.
[0012]
In addition, as described in JP-A-59-81043, in order to eliminate the influence of cracks and chips existing in the insulating layer, increasing the thickness of the insulating layer causes a decrease in cutting performance and a deterioration in fracture resistance. Will cause problems.
[0013]
The present invention aims to solve such problems.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, in the cutting tool with a sensor according to claim 1, in the cutting tool with a sensor, an insulating layer is provided on the surface of the conductive base material, and a sensor circuit made of a conductive film is formed thereon. The insulating layer is characterized in that two or more layers made of aluminum oxide are successively laminated .
[0016]
In the sensor-equipped tool, it is desirable that the thickness of the layer made of aluminum oxide on the sensor circuit side of the insulating layer is thicker than the thickness of the layer made of aluminum oxide on the conductive base material side.
[0017]
In the cutting tool with a sensor according to claim 3 , an insulating layer in which two or more layers made of aluminum oxide are continuously laminated is provided on the surface of the conductive base material, and a sensor circuit made of the conductive film is formed thereon. A cutting tool with a sensor , wherein the conductive material present in the insulating layer is discontinuous in the thickness direction of the insulating layer.
[0018]
In the method for producing a cutting tool with a sensor according to claim 4 , in the method for producing a cutting tool with a sensor, wherein an insulating layer is provided on the surface of the conductive base material and a sensor circuit made of a conductive film is formed thereon. In addition, an insulating layer is formed on the conductive base material, and then the surface is etched and / or washed to further form an insulating layer.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the invention according to each claim will be described using a throwaway tool as an example. Application to a drill or the like is also possible.
[0020]
FIG. 1 is a view showing an embodiment of a cutting tool with a sensor according to claim 1. In FIG. 1, 6 is a conductive film, 7 is a second insulating layer, 8 is a first insulating layer, 9 is a conductive base material, 10 is a defective portion such as a crack or pinhole in the second insulating layer, Reference numeral 11 denotes a defect portion such as a crack or pinhole in the first insulating layer portion, and reference numeral 12 denotes a defect portion such as conductive particles in the first insulating layer portion.
[0021]
In this cutting tool with a sensor, two or more continuous insulating

layers

7 and 8 are stacked. By doing so, the conductive film 6 is prevented from entering the defects 11 and 12 when the conductive film of the next process is produced, and the short circuit between the conductive base material 9 and the conductive circuit is prevented. Can function normally. Defects 11 and 12 formed during the production of the first insulating layer 8 can be filled or covered with the second insulating layer 7. In addition, the defect 10 formed during the production of the second insulating layer 7 is caused by a short-circuiting factor component during the production of the conductive film 6, but the first insulating layer 8 causes a short circuit between the conductive base material 9 and the conductive film 6. I can stop.
[0022]
Examples of the conductive base material 9 include an aluminum oxide sintered body, a silicon nitride sintered body, a cermet, a cemented carbide, a cubic boron nitride sintered body (CBN / Cubic Boron Nitride), and a diamond sintered body (PCD). / Polycrystalline Diamond), and the conductive base material 9 is made of one or more kinds of carbides, nitrides, carbonitrides of the group 4a, 5a, and 6a elements of the periodic table 4a, 5a, and 6a by PVD and / or CVD. A tool coated with any one hard film (not shown) of oxide can be used.
[0023]
As the aluminum oxide sintered body, 2 to 40 wt% of TiC, 0.01 to wt% of at least one of oxides of Fe, Ni, and Co, and the balance of Al ₂ O ₃ and inevitable impurities are oxidized. An aluminum sintered body can be used.
[0024]
As the silicon nitride sintered body, Al is 1.5 to 10 mol% in terms of Al ₂ O ₃ , Ti carbide, nitride, carbonitride is 30 to 80 mol%, and the balance is silicon nitride and rare earth oxide. It is possible to use a silicon nitride-based sintered body having a ratio of 10% by weight or less with respect to silicon nitride and 10% by mole or less of impurity oxygen in terms of SiO ₂ .
[0025]
As the cermet, Ti is contained in a proportion of 50 to 80% by weight in terms of carbide, nitride or carbonitride, and Group 6a element in the periodic table is contained in a proportion of 10 to 40% by weight in terms of carbide (nitrogen / carbon + nitrogen). ) TiCN group cermet comprising 70 to 90% by weight of a hard phase component having an atomic ratio in the range of 0.4 to 0.6 and 10 to 30% by weight of a binder phase component comprising an iron group metal. is there.
[0026]
Examples of the cemented carbide include those composed of a hard phase and a binder phase, and the hard phase is tungsten carbide, or 5 to 15% by weight of tungsten carbide, carbides of the metals in groups 4a, 5a, and 6a of the periodic table. The binder phase is mainly composed of an iron group metal such as Co, and is contained in a total amount of 5 to 15% by weight, for example.
[0027]
As the coating layer (not shown), Ti carbide, nitride, carbonitride is formed from 0.1 μm to 10 μm, Al oxide is formed from 0.1 μm to 10 μm, TiAl nitride is formed from 0.1 μm to 10 μm, and the like. One type or two or more types of these hard films are coated on a base material such as the above cemented carbide, cermet or ceramic.
[0028]
The insulating

layers

7 and 8 that insulate the conductive base material 9 and the conductive film 6 are formed by a CVD method, a PCVD method, an ion plating method, a PVD method such as sputtering, vapor deposition, or a plating method. When the insulating

layers

7 and 8 are formed, for example, by sputtering, it is performed in an Ar atmosphere. The film forming conditions are such that pre-sputtering is performed for 1 minute or longer, base material etching is performed for 1 minute or longer, and target pre-sputtering is performed for 1 minute or longer in order to remove dirt on the target. Depending on the time, it takes between 5 and 200 minutes. Further, in the case of forming by the CVD method, H ₂ is used as a carrier gas, CO ₂ , HCl, AlCl ₃ is used as a reaction gas, the film forming temperature is between 850 ° C. and 1100 ° C., and the furnace pressure is 40 mbar to Perform between 300 mbar. The insulating

layers

7 and 8 may be made of an insulating material such as aluminum nitride, silicon nitride, zirconium oxide, or titanium oxide.
[0029]
The multilayer insulating

layers

7 and 8 are preferably produced by this method. The total thickness of the insulating

layers

7 and 8 is preferably 0.1 to 20 μm. The reason why the insulating

layers

7 and 8 are 0.1 μm or more is that the insulating effect may be lost if the thickness is less than 0.1 μm. The thickness of the insulating

layers

7 and 8 is 20 μm or less, preferably 10 μm or less. This is because when the thickness of the insulating

layers

7 and 8 is 20 μm or more, the cutting performance (particularly, chipping resistance) is adversely affected.
[0030]
The conductive film 6 is a periodic table 4a, 5a, 6a group metal such as Ti, Zr, V, Nb, Ta, Cr, Mo, W, an iron group metal such as Co, Ni, Fe, or a metal material such as Al. TiC, VC, NbC, TaC, Cr 3 C 2, Mo 2 C, WC, W 2 C, TiN, VN, NbN, TaN, CrN, TiCN, VCN, NbCN, TaCN, periodic table 4a such CrCN, 5a , 6a group metal carbide, nitride, carbonitride, (Ti, Al) N and the like. Among these, TiN has a strong joining force to the base material of the throw-away tip, does not react with the work material, the electrical resistance value of the sensor always shows a predetermined value, the degree of wear of the throw-away tip, whether or not there is a defect Can be detected accurately, the formation of scratches by reaction products on the work surface of the work material can be effectively prevented, oxidation resistance is excellent, and the electrical resistance of the sensor changes due to oxide formation. However, it can be suitably used for reasons such as the degree of wear of the throw-away tip, the presence or absence of occurrence of a defect, and the like.
[0031]
By using a CVD method, a PVD method such as ion plating, sputtering, vapor deposition, or a plating method, a conductive film is deposited to a predetermined thickness on almost the entire surface of the base material of the throw-away chip. Thereafter, the conductive film is processed into a predetermined pattern by laser processing to form a conductive film 6.
[0032]
If the conductive film 6 is thin with a thickness of less than 0.05 μm, the bonding to the surface of the base material becomes weak and the electrical resistance value of the sensor becomes high, so that the wear degree and chipping of the throw-away tip can be accurately detected. There is a risk that it becomes difficult. Further, if an attempt is made to form a conductive film having a thickness exceeding 20 μm, a large stress is generated and remains in the conductive film during the formation, and the residual stress causes weak bonding of the conductive film 6 to the base material surface. There is a risk of becoming.
[0033]
Then, a sensor circuit is formed by a method such as laser processing so that the rake face and flank face of the blade edge are parallel to the edge line of the blade edge. Although it can be considered that the sensor width is generally 0.01 mm to 0.5 mm, an arbitrary width may be given depending on the lifetime setting. As a result, a sensor circuit with good electrical insulation can be manufactured.
[0034]
Moreover, as the insulating

layers

7 and 8, it is desirable to use aluminum oxide and / or zirconium oxide from the viewpoint of excellent oxidation resistance and wear resistance.
[0035]
FIG. 2 is a view showing an embodiment of a cutting tool with a sensor according to a third aspect. In FIG. 2, 13 is a conductive film, 14 is a second insulating layer, 15 is a first insulating layer, 16 is a conductive base material, 17 is a defective portion such as a crack or pinhole in the second insulating layer, Reference numeral 18 denotes a defective portion such as a crack or pinhole in the first insulating layer portion, and 19 denotes a defective portion such as conductive particles in the first insulating layer portion. By making the second insulating layer 14 thicker than the thickness of the first insulating layer 15, it is possible to more efficiently fill the defects 18 that are formed when the first insulating layer 15 is manufactured. As a result, a short circuit between the conductive base material 16 and the conductive circuit can be prevented, and the sensor circuit can function normally.
[0036]
FIG. 3 is a view showing an embodiment of a cutting tool with a sensor according to claim 4. In FIG. 3, 20 is a conductive film, 21 is an insulating layer, 22 is a conductive base material, 23 is a conductive film material present in cracks or pinholes, 24 is a conductive material, and the conductive materials 23 and 24 are By being discontinuous between the conductive film 20 and the conductive base material 22, a short circuit between the conductive film 20 and the conductive base material 22 can be prevented. It is important that the conductive materials 23 and 24 existing in pinholes and cracks in the middle of the conductive base material 22 and / or the conductive film 20 in the thickness direction of the insulating layer 21 are discontinuous. As a result, no short circuit occurs between the conductive base material 22 and the conductive circuit, and the sensor circuit can function normally.
[0037]
Next, a method for producing a cutting tool with a sensor according to claim 5 will be described. For example, in FIG. 1, before forming the second insulating layer 7, an etching or cleaning process is performed, so that defects 11 and 12 such as cracks and pinholes in the first insulating layer 8 are formed in the second layer. The insulating layer 7 facilitates plugging. By making etching or cleaning where the pinhole is formed when the first insulating layer 8 is formed, the surface of the pinhole part is activated to facilitate the formation of the second and subsequent insulating layers 7, The pinhole portion in the first insulating layer 8 can be closed with the second insulating layer 7 to prevent a short circuit between the conductive base material 9 and the conductive sensor circuit, and to function normally as a sensor circuit.
[0038]
【Example】
Example 1
As an example, the following five samples 1 were produced. Al ₂ O ₃ —TiC ceramic was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 3 μm was formed as the first layer by sputtering. The sputtering apparatus was a high-frequency sputtering apparatus in an Ar atmosphere. Pre-sputtering was performed for 3 minutes, etching of the base material was performed for 12 minutes, target pre-sputtering was performed for 15 minutes, and film formation was performed for 60 minutes.
[0039]
Next, a 3 μm aluminum oxide film was formed by sputtering as the second layer. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. Thereafter, TiN was deposited by PVD to produce a circuit, and a sensor circuit with good electrical insulation could be produced. The electrical insulation property was investigated by the method shown in FIG. In FIG. 4, 27 is a conductive base material, 26 is a first insulating layer, 25 is a second insulating layer, and 28 is a tester. Table 1 shows the measurement results of electrical resistance.
[0040]
Five samples 2 below were produced as samples of the prior art. An Al ₂ O ₃ —TiC ceramic base material was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 3 μm was formed by sputtering. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. When a circuit was fabricated by forming a conductive film by depositing TiN with PVD, a sensor circuit with poor electrical insulation was obtained. The electrical insulation was measured by the method shown in FIG. Table 1 shows the measurement results of electrical resistance.
[0041]
[Table 1]

[0042]
-Example 2-
Five samples 3 were prepared as examples of the present invention. An Al ₂ O ₃ —TiC ceramic base material was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 3 μm was formed as the first layer by sputtering. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. Next, a 5 μm aluminum oxide film was formed by sputtering as the second layer. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was pre-sputtered for 15 minutes, and the film was formed for 100 minutes. Thereafter, TiN was deposited by PVD to produce a circuit, and a sensor circuit with good electrical insulation could be produced. The electrical insulation property was investigated by the method shown in FIG. Table 2 shows the measurement results of electrical resistance.
[0043]
Five samples 4 below were produced as samples. An Al ₂ O ₃ —TiC ceramic base material was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 3 μm was formed by sputtering. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. Next, a 3 μm aluminum oxide film was formed by sputtering as the second layer. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. When a circuit is fabricated by forming a conductive film by depositing TiN with PVD, a sensor circuit with poor electrical insulation can be obtained. The electrical insulation property was investigated by the method shown in FIG. Table 2 shows the measurement results of electrical resistance.
[0044]
[Table 2]

[0045]
-Example 3-
The following samples were produced as examples of the present invention. An Al ₂ O ₃ —TiC ceramic base material was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 1 μm was formed by sputtering as the first layer. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 20 minutes. Next, a 5 μm aluminum oxide film was formed by sputtering as the second layer. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was pre-sputtered for 15 minutes, and the film was formed for 100 minutes. Thereafter, TiN was formed into a conductive film by PVD, a circuit was fabricated and the cross section was confirmed. As shown in FIG. 2, conductive film material 23, conductive material 24 present in pinholes and cracks in the insulating layer. Was confirmed to be discontinuous in the thickness direction of the insulating layer.
Example 4
Five samples 5 below were produced as examples of the present invention. An Al ₂ O ₃ —TiC ceramic base material was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 3 μm was formed as the first layer by sputtering. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. Next, a 3 μm aluminum oxide film was formed by sputtering as the second layer. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. Thereafter, TiN was deposited by PVD to produce a circuit, and a sensor circuit with good electrical insulation could be produced. The electrical insulation property was investigated by the method shown in FIG. Table 3 shows the measurement results of electrical resistance.
[0046]
The following five samples 5 were produced as prior art samples. An Al ₂ O ₃ —TiC ceramic base material was used as the conductive base material. As an insulating layer that insulates the conductive base material from the conductive film, an aluminum oxide film having a thickness of 3 μm was formed by sputtering. As the sputtering apparatus, pre-sputtering was performed for 3 minutes in an Ar atmosphere using a high-frequency sputtering apparatus, the base material was etched for 12 minutes, the target was subjected to pre-sputtering for 15 minutes, and film formation was performed for 60 minutes. Next, a 3 μm aluminum oxide film was formed by sputtering as the second layer. As a sputtering apparatus, film formation was performed for 60 minutes in an Ar atmosphere using a high-frequency sputtering apparatus. When a circuit is fabricated by forming a conductive film by depositing TiN with PVD, a sensor circuit with poor electrical insulation can be obtained. The electrical insulation property was investigated by the method shown in FIG. Table 3 shows the measurement results of electrical resistance.
[0047]
[Table 3]

[0048]
【The invention's effect】
As described above, in the sensor with a cutting tool according to claim 1, wherein the insulating layer to form a conductive circuit, since made of a laminate of two or more layers in succession a layer of aluminum oxide, the next step When the conductive film is produced, the conductive film is prevented from entering into the defect, and the conductive base material and the conductive circuit are not short-circuited, so that the sensor circuit can function normally.
[0050]
Further, in the sensor with the cutting tool according to claim 2, since increasing the thickness of the sensor circuit side of the insulating layer than a thickness of the layer of aluminum oxide of the conductive base material side, aluminum oxide for the first layer in the insulating layer The layer made of (the conductive base material side) is made as thin as possible, and defects such as pinholes formed thereby are blocked by increasing the thickness of the second layer made of aluminum oxide (the conductive circuit side). be able to.
As a result, a short circuit between the conductive base material and the conductive circuit can be prevented, and the sensor circuit can function normally.
In other words, in the PVD method, where there is a defect such as a pinhole, there is a disadvantage that it is difficult to form a film, and since it is used as a tool, considering the deterioration of chipping resistance due to thickening, the thickness of the insulating layer is The thinner it is, the better.
[0051]
Moreover, in the cutting tool with a sensor which concerns on Claim 3 , the electroconductive substance which exists in a pinhole and a crack in the middle which consists of the electroconductive base material and / or electrically conductive film of the thickness direction of an insulating layer is discontinuous. The short circuit between the conductive base material and the conductive circuit is prevented, and the sensor circuit can function normally.
[0052]
In the method for producing a cutting tool with a sensor according to claim 4 , after forming an insulating layer on the conductive base material, the surface is etched and / or washed to further form an insulating layer.
That is, it is known that defects such as pinholes occur at locations where the surface is not activated due to contamination of the base material or residual moisture.
Therefore, by making etching and cleaning where the pinhole is formed when the first insulating layer is formed, and activating the surface of the pinhole portion, it becomes easier to form the second and subsequent insulating layers. The pinhole portion can be blocked with a second insulating layer to prevent a short circuit between the conductive sensor circuits from the conductive base material and function normally as a sensor circuit.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a cutting tool with a sensor according to claim 1;
FIG. 2 is a cross-sectional view showing an embodiment of a cutting tool with a sensor according to claim 3;
FIG. 3 is a sectional view showing an embodiment of a cutting tool with a sensor according to claim 4;
FIG. 4 is a diagram showing an outline of a method for measuring electrical insulation.
FIG. 5 is a cross-sectional view showing a conventional cutting tool with a sensor.
[Explanation of symbols]
1: Conductive film 2: Insulating layer 3: Conductive base material 4: Defects such as cracks and pinholes 5: Defects such as conductive particles 6: Conductive film 7: Second insulating layer 8: First insulating layer 9 : Conductive base material 10: Defects such as cracks and pinholes in the second insulating layer part 11: Defects such as cracks and pinholes in the first layer insulating layer 12: Conductivity of the first insulating layer part Defects 13 such as particles: Conductive film 14: Second insulating layer 15: First insulating layer 16: Conductive base material 17: Defect 18: 1 layer such as crack or pinhole in second insulating layer Defects such as cracks and pinholes in the first insulating layer 19: Defects such as conductive particles in the first insulating layer 20: Conductive film 21: Insulating layer 22: Conductive base material 23: In cracks and pinholes Conductive film material 24: conductive material 25: conductive film 26: insulating layer 27: conductive base material 28: tester

Claims

In a cutting tool with a sensor formed by providing an insulating layer on the surface of a conductive base material and forming a sensor circuit made of a conductive film thereon,
The insulating layer, the sensor with the cutting tool, characterized in that it consists those consecutive layers of aluminum oxide are laminated two or more layers.

The cutting tool with a sensor according to claim 1 , wherein the thickness of the layer made of aluminum oxide on the sensor circuit side is thicker than the thickness of the layer made of aluminum oxide on the conductive base material side in the insulating layer.

A cutting tool with a sensor in which an insulating layer in which two or more layers made of aluminum oxide are continuously laminated is provided on the surface of a conductive base material, and a sensor circuit made of a conductive film is formed thereon,
A cutting tool with a sensor, wherein the conductive material present in the insulating layer is discontinuous in the thickness direction of the insulating layer.

In a method for manufacturing a cutting tool with a sensor, in which an insulating layer is provided on a surface of a conductive base material and a sensor circuit made of a conductive film is formed thereon, the insulating layer is formed on the conductive base material, and then the surface is formed. A method for producing a cutting tool with a sensor, wherein an insulating layer is further formed by etching and / or cleaning.