JP4357657B2

JP4357657B2 - Manufacturing method of drilling tool

Info

Publication number: JP4357657B2
Application number: JP22730299A
Authority: JP
Inventors: 國雄安心院
Original assignee: 株式会社ハウスビーエム
Priority date: 1999-06-22
Filing date: 1999-08-11
Publication date: 2009-11-04
Anticipated expiration: 2019-08-11
Also published as: JP2001062783A

Description

【０００１】
【発明の属する技術分野】
本発明は、壁、天井、その他の加工物に孔を開けるための孔開け工具及びその製造方法に関するものである。
【０００２】
【従来の技術】
従来、上記のような孔開け工具としては、略円筒状のボディの端部に複数の切削刃をもつ刃物を有し、この刃物が工具本体に装着された状態で当該工具本体が回転駆動機などの駆動源に連結されることにより、工具全体が一体に回転駆動されるようにしたものが一般に知られている。さらに近年は、単一の工具本体に互いに加工径の異なる複数種の刃物を装着できるようにしたり、刃物の寿命延長等のために刃物軸方向両端に前記切削刃を設けた刃物を使用したりするために、その刃物を工具本体に対して着脱可能にする工夫が検討されている。
【０００３】
その構造例を図８（ａ）（ｂ）に示す。この工具は、図略の駆動源に連結される工具本体８０を有し、その先端部８２に中心位置決め用のセンタードリル８４が着脱可能に装着されるとともに、前記先端部８２の外側に刃物９０が着脱可能に装着されるようになっている。
【０００４】
この刃物９０は、円筒状のボディ９１を有し、その先端部に複数の切削刃９２が周方向に並んだ状態で固定される一方、刃物９０の基部は前記工具本体８０の先端部８２に外嵌される筒状取付部分９４とされている。この筒状取付部分９４には、これを径方向に貫通する２つのねじ孔９４ａが180°間隔で設けられ、各ねじ孔９４ａ内に止めねじ９６が螺合挿通可能となっている。一方、前記工具本体先端部８２の外周面には、その２個所が平面状に切欠かれることにより回り止め係合部８２ａが形成されており、これら回り止め係合部８２ａにそれぞれ前記止めねじ９６の端部が係合されることにより、工具本体８０に対する刃物９０の相対回転が規制され、両者が一体に回転駆動されるようになっている。
【０００５】
この孔開け工具の使用要領は次のとおりである。
【０００６】
▲１▼ 予め刃物９０の各ねじ孔９４ａ内に止めねじ９６を螺合挿入させておく。その際、各止めねじ９６はある程度径方向外側に位置させてその端部が筒状取付部分９４の内周面よりも内方に突出しないようにしておく。
【０００７】
▲２▼ 工具本体先端部８２の外側に刃物９０の筒状取付部分９４を嵌合する。そして、同先端部８２の回り止め係合部８２ａと止めねじ９６との位置が合致するように工具本体８０と刃物９０との相対角度を調節した上で、各止めねじ９６を締込み方向に回して内方に変位させ、その端部を各回り止め係合部８２ａに係合させる（工具本体８０への刃物９０の取付完了。）。
【０００８】
▲３▼ 工具本体８０を図略の回転駆動機に連結し、孔開け工具全体を回転駆動する。この状態でまずセンタードリル８４を施工面に押付けることにより、加工孔の芯出し（中心位置決め）が行われ、次いでその周囲を刃物９０の切削刃９２が切削することにより、刃物９０と略同径の孔が開けられる。
【０００９】
【発明が解決しようとする課題】
前記孔開け工具では、工具本体先端部８２に刃物９０の筒状取付部分９４を外嵌した後、その止めねじ９６の周方向位置と回り止め係合部８２ａの周方向位置とを合致させる周方向の位置決め作業が必要があるが、かかる外嵌状態では回り止め係合部８２ａが筒状取付部分９４の内側に隠れて外から見えないので、前記位置決め作業は容易でない。また、位置決めをした後も、両方の止めねじ９６をそれぞれ別個に回転操作する必要があり、非常に手間がかかる。
【００１０】
さらに、工具本体８０に対する刃物９０の相対回転の規制はすべて止めねじ９６と工具本体８０との係合によってなされているので、使用時の振動等で双方の止めねじ９６が緩んで回り止め係合部８２ａから離脱した場合には、前記相対回転の規制がなくなり、工具本体８０から刃物９０へのトルク伝達が不能になって施工を中断しなければならなくなる。
【００１１】
さらに、この工具を製造するにあたっては、筒状取付部分９４に２つのねじ孔９４ａを設けなければならず、その製造にも手間を要する。
【００１２】
本発明は、このような事情に鑑み、工具本体への刃物の着脱操作が簡単でその取付信頼性も高い孔開け工具を簡単に製造するための方法を提供することを目的とする。
【００１３】
【課題を解決するための手段】
上記課題を解決するための手段として、本発明は、駆動源に連結される工具本体と、この工具本体の外側に嵌合可能な筒状取付部分を有し、その嵌合状態で前記工具本体と一体に回転するように当該工具本体に固定される刃物とを備え、前記筒状取付部分にこの筒状取付部分を径方向に貫通するねじ孔を設け、前記筒状取付部分の内周面において前記ねじ孔と対向する位置に取付孔を設け、この取付孔内に回り止め部材を当該回り止め部材が筒状取付部分の内周面から内方に突出する状態で取付ける一方、前記工具本体において前記筒状取付部分が嵌合される外周面に、前記回り止め部材の突出部と係合することにより工具本体と刃物との相対回転を規制する回り止め係合部と、この回り止め係合部と前記回り止め部材とが係合される角度位置で前記ねじ孔と合致する位置に位置し、当該ねじ孔に螺合挿通される止めねじと係合されるねじ係合部とを設けた孔開け工具を製造するための方法であって、前記刃物の筒状取付部分にこの筒状取付部分を径方向に貫通するねじ孔を設け、このねじ孔に別の孔開け工具を挿通することにより前記筒状取付部分の内周面に取付孔を設け、この取付孔内に前記ねじ孔を通じて回り止め部材を挿入し、固定するものである。
【００１４】
この方法により製造された孔開け工具によれば、前記回り止め部材と回り止め係合部とが係合する相対角度位置で工具本体の外周面に刃物の筒状取付部分を嵌合すれば、この筒状取付部分側のねじ孔の位置と工具本体外周面側のねじ係合部の位置とが自動的に合致するので、そのままねじ孔内で止めねじを内方に進行させて前記ねじ係合部に係合させることにより、工具本体への刃物の装着を完了することができる。従って、従来の工具に比べて工具本体と刃物との周方向の位置合わせが数段容易であり、しかも、単一の止めねじを回転操作するだけで、この止めねじと回り止め部材との双方により確実に刃物を工具本体に相対回転不能に固定することができる。
【００１５】
また、従来のように止めねじのみによって刃物の回り止めをするのではなく、筒状取付部分の内周面に形成した取付孔内に取付けた回り止め部材によって刃物の回り止めをしているので、工具の振動などで止めねじが緩んでも、回り止め部材による相対回転規制は続けられる。従って、施工を中断しなくても済み、装着状態での信頼性が高い。
【００１６】
しかも、前記方法によれば、前記ねじ孔と取付孔とを互いに対向する位置に設けるようにすることにより、前記孔開け工具を簡単に製造することができる。すなわち、前記刃物の筒状取付部分にこの筒状取付部分を径方向に貫通するねじ孔を設け、このねじ孔に別の孔開け工具を挿通することにより前記筒状取付部分の内周面に取付孔を設け、この取付孔内に前記ねじ孔を通じて回り止め部材を挿入し、固定するという方法によって、筒状取付部分の内側スペースがかなり狭いにもかかわらず、はじめに形成したねじ孔を巧みに利用して、取付孔及び回り止め部材を簡単に前記筒状取付部分の内周面に設けることができる。
【００１７】
ここで、前記筒状取付部分内周面からの回り止め部材の突出量を決める手段としては、前記取付孔を有底とし、その底部に突き当たるまで前記回り止め部材を取付孔内に挿入するようにしてもよいし、前記回り止め部材にその挿入端部よりも断面形状の大きい頭部を形成しておき、この頭部が前記筒状取付部分の内周面に当たる深さまで取付孔内に当該回り止め部材を挿入するようにしてもよい。後者の場合には、回り止め部材の頭部寸法がそのまま回り止め部材の突出量になるので、当該突出量の設定が非常に容易であるという利点がある。
【００１８】
また、前記取付孔内への回り止め部材の取付手段は問わず、単なる圧入でもよいし、接着剤その他の手段で回り止め部材を固定するようにしてもよい。
【００１９】
一方、工具本体側の前記回り止め係合部は前記工具本体の外周面の一部を切欠くことにより簡単に形成することが可能である。
【００２０】
本発明は、工具本体に刃物が着脱可能に装着される種々の孔開け工具の製造に適用が可能である。具体的には、前記工具本体はその先端部にセンタードリルが設けられるものであり、前記刃物は、前記センタードリルの周囲をこれと同軸状態で覆う略円筒状をなし、その先端部に切削刃をもつような工具の製造に特に好適である。
【００２１】
例えば、前記刃物がその両端に前記切削刃を有し、中間部に前記筒状取付部分を有するものでは、工具本体と刃物との着脱作業を簡単にすることにより、刃物両端の切削の使い分けを簡単に行うことが可能になる。
【００２２】
【発明の実施の形態】
本発明の好ましい実施の形態を図面に基づいて説明する。
【００２３】
ここに示す孔開け工具は、図１及び図２に示す工具本体１１と、図１及び図３に示す刃物２０とを備えている。
【００２４】
工具本体１１の後部には、図略の回転駆動機に連結される駆動連結部１１ａが形成され、前部にはセンタードリル（ドリルビット）１２が取付けられている。具体的には、図２に示すように、工具本体１１に、その中心軸に沿って前方に開口するドリル取付孔１１ｂと、工具本体外周面から前記ドリル取付孔１１ｂの奥部につながるねじ孔１１ｃとが形成されている。一方、センタードリル１２の前部にはドリル刃１２ａが、後部には丸軸状のシャンク部１２ｂが各々形成され、その後端部外周面にその周方向一部を切り欠いた切欠１２ｃが形成されており、そのシャンク部１２ｂを前記ドリル取付孔１１ｂ内に挿入した状態で、前記ねじ孔１１ｃ内の止めねじ１４を締めて前記切欠１２ｃに係合させることにより、工具本体１１にセンタードリル１２が固定されるようになっている。
【００２５】
なお、前記センタードリル１２のドリル刃１２ａの周囲には切り屑除去用の螺旋状ばね１８が装着されている。
【００２６】
工具本体１１の前端部は、その後側部分よりも小径とされ、その境界に段部１１ｄが形成されている。さらに、その前端部にはこれを径方向に貫通するテーパー孔１１ｔが設けられ、このテーパー孔１１ｔの裏側（反対側）には、その外周面を平面で切り欠いた形状の回り止め係合部１１ｅが形成されている。前記テーパー孔１１ｔは、径方向内側に向かうに従って縮径する方向のテーパー状内周面を有している。
【００２７】
刃物２０は、前後対称の略円筒状をなしている。その前後両端には周方向に並ぶ複数の切削刃２１が設けられ、その奥側に切り屑排出用の貫通孔２２が適所に設けられている。刃物２０の前後方向中間部は、他の部分よりも肉厚が大きい（外径が大きくて内径が小さい）筒状取付部分２４とされ、その内側に前記工具本体１１の前端部が嵌入可能、すなわち工具本体１１の前端部外側に筒状取付部分２４が嵌合可能となっている。そして、この筒状取付部分２４の内周部後端と前記工具本体１１の段部１１ｄとの当接によって、工具本体１１に対する刃物２０の軸方向の位置決めがなされる。
【００２８】
前記筒状取付部分２４には、これを径方向に貫通するねじ孔２４ａが設けられ、このねじ孔２４ａ内に止めねじ２６が螺合挿入されるようになっている。止めねじ２６は、その外周面に前記ねじ孔２４ａと螺合可能な雄ねじ２６ａを有し、頭部にはレンチ３０を挿入するための凹部２６ｂが設けられている。止めねじ２６の内側端部は前記テーパー孔１１ｔと略同等のテーパー角度をもつ先すぼみのテーパー部２６ｔとされ、このテーパー部２６ｔが前記テーパー孔１１ｔ内に圧入されることにより、そのテーパー作用で工具本体１１が先端側に引張られて段部１１ｄが筒状取付部分２４の後端内周部に押付けられ、これにより工具本体１１に対する刃物２０の固定が行われるように、ねじ孔２４ａとテーパー孔１１ｔとの軸方向に関する相対位置関係が設定されている。
【００２９】
筒状取付部分２４の内周面において、前記ねじ孔２４ａの延長線上の位置（すなわちねじ孔２４ａと対向する位置）には、有底円形状の取付孔２４ｂが設けられ、この取付孔２４ｂ内に回り止めピン（回り止め部材）２８が圧入、固定されている。この回り止めピン２８の頭部は前記筒状突出部分２４の内周面から若干内方に突出しており、この突出頭部が前記工具本体１１の回り止め係合部１１ｅに係合することにより、工具本体１１に対する刃物２０の相対的な角度位置が規制されるようになっており、その規制位置で前記テーパー孔１１ｔの位置とねじ孔２４ａの位置とが周方向に合致するように、両位置が設定されている。
【００３０】
なお、図１などにおいて１６は、工具本体１１の外周面に鍔状に設けられたゴム等からなる刃物カバーであり、この刃物カバー１６によって、使用しない側（後端側）の切削刃２１が作業者側に露出するのが防止されるようになっている。
【００３１】
次に、この孔開け工具の使用要領例を説明する。
【００３２】
▲１▼ 予めねじ孔２４ａ内に止めねじ２６を螺合挿入しておくが、この止めねじ２６の内側端部が筒状突出部分２４の内周面から内方に突出しないように、当該止めねじ２６の位置を径方向外側よりに控えておく。
【００３３】
▲２▼ 回り止めピン２８と回り止め係合部１１ｅとが係合する角度位置で筒状取付部分２４を工具本体１１の前端部外側に嵌合する。これにより、工具本体１１側のテーパー孔１１ｔと筒状取付部分２４側のねじ孔２４ａとが合致する。この嵌合は、前記回り止めピン２８と回り止め係合部１１ｅとが係合する角度位置でしかできないので、当該嵌合を行えばテーパー孔１１ｔと筒状取付部分２４とが自動的に位置合わせされることになる。従って、その位置合わせ作業を特別に行う必要がない。しかも、この嵌合によって、工具本体１１に対する刃物２０の相対回転が確実に規制された状態になる。
【００３４】
▲３▼ 止めねじ２６の凹部２６ｂにレンチ３０を差込み、当該止めねじ２６を回転操作して止めねじ２６を内方へ締め込む。これにより、止めねじテーパー部２６ｔの外周面と工具本体１１のテーパー孔１１ｔの内周面とが前側（図４（ａ）では左側）で圧接し、そのテーパー作用によって工具本体１１が前側に引張られる。すなわち、工具本体１１の段部１１ｄが筒状取付部分２４の後端内周部に押付けられ、これにより刃物２０が工具本体１１に完全に固定される。従って、単一の止めねじ２６を回転操作するだけで刃物２０の固定ができる。
【００３５】
▲４▼ 工具本体１１の駆動連結部１１ａを図略の回転駆動機に連結し、工具全体を高速回転駆動する。この状態でまずセンタードリル１２のドリル刃１２ａを施工面に押付けて穿孔することにより、加工孔の中心位置が定められ、次いで刃物２０の切削刃２１が前記施工面に押付けられることにより、本穿孔が行われる。
【００３６】
ここで、もし仮に施工中の振動などで止めねじ２６が緩んでも、回り止めピン２８と回り止め係合部１１ｅとの係合によって工具本体１１に対する刃物２０の相対回転は規制され続ける（すなわち工具本体１１から刃物２０へのトルク伝達が続けられる）ので、支障なく施工を続行できる。前記止めねじ２６は、施工が終わった後に締め直せばよい。
【００３７】
▲５▼ 例えば刃物２０の交換や刃物２０を逆向きにする（すなわち反対側の切削刃２１を使う）目的で刃物２０を取り外したい場合には、止めねじ２６を緩め方向（止めねじ２６が径方向外側に変位する方向）に回してそのテーパー部２６ｔをテーパー孔１１ｔから待避させればよい。これにより、筒状取付部分２４を工具本体１１の前端部から前方へ簡単に取り外すことができる。
【００３８】
以上のように、この実施の形態にかかる孔開け工具によれば、前記図８に示した従来工具よりも数段簡単な操作で刃物２０の着脱を行うことができ、また、取付状態での信頼性も大幅に向上する。しかも、この孔開け工具における刃物２０の取付構造は、例えば次の方法によって簡単に製造することができる。
【００３９】
▲１▼ 筒状取付部分２４の適所にねじ孔２４ａを設ける。
【００４０】
▲２▼ ねじ孔２４ａに例えば図５（ａ）に示すようなブッシュ３２を外側から挿通し、その先端を前記ねじ孔２４ａと対向する内周面に突き当てる。
【００４１】
▲３▼ 同図（ａ）に示すドリル３４を前記ブッシュ３２の内側に挿入し、このドリル３４の先端部によって前記内周面に有底の取付孔２４ｂを形成する。
【００４２】
▲４▼ ドリル３４をブッシュ３２から抜き、次いで、このブッシュ３２を通して取付孔２４ｂ内に回り止めピン２８を嵌め込む。圧入する場合には、前記ブッシュ３２内に押棒を突っ込むなどして回り止めピン２８に上から圧力を加える（同図（ｂ）の矢印参照）。
【００４３】
すなわち、この孔開け工具では、ねじ孔２４ａと対向する位置に取付孔２４ｂを設け、これに回り止めピン２８を取付けるようにしているので、最初に設けたねじ孔２４ａを有効に利用することにより、筒状取付部分２４内の狭いスペースでも、その内周面に取付孔２４ｂ及び回り止めピン２８を難なく設けることができるのである。
【００４４】
ところで、前記図１〜図５に示す構造において、筒状取付部分２４の内周面からの回り止めピン２８の突出量を正確に決めるには、有底取付孔２４ｂの深さ寸法を前記回り止めピン２８の全長からその目標突出量を差し引いた寸法に合わせた上で、この取付孔２４ｂの底部に回り止めピン２８が突き当たる深さまで当該ピン２８を当該取付孔２４ｂに挿入するようにすればよい。しかしながら、前記取付孔２４ｂの深さ寸法を目標寸法に正確に合せることは容易でなく、誤差が生じ易い。
【００４５】
これに対し、図６及び図７に示すように、予め回り止めピン２８にその挿入端部（図６及び図７では下端部）よりも断面形状の大きい（図例では大径円の）頭部２８ａを形成し、かつ、その頭部２８ａの高さ寸法ｈを目標突出量に合せておけば、この頭部２８ａが筒状取付部分２４の内周面に当たる深さまで回り止めピン２８を取付孔２４ｂ内に挿入するだけで、図７（ｂ）に示すように、取付孔２４ｂの深さ寸法ｄに関係なく（極端には取付孔２４ｂが筒状取付部分２４を貫通するものであっても）、回り止めピン２８の突出量を目標突出量すなわち頭部２８ａの高さ寸法ｈに合致させることができる。このように回り止めピン２８の頭部２８ａの高さ寸法を目標突出量に合せることは、前記取付孔２４ｂの深さ寸法を目標寸法に合せるよりも格段に容易である。
【００４６】
ここで、前記回り止めピン２８の本体及びその頭部２８ａの断面形状は必ずしも円に限られない。当該形状をどのように設定するにしろ、頭部２８ａの断面形状を挿入端部よりも大きくして当該頭部２８ａが必ず筒状取付部分２４の内周面に突き当たるように構成すれば、上述の効果を得ることができる。
【００４７】
その他、本発明は例として次のような実施の形態をとることも可能である。
【００４８】
(1) 本発明では、刃物２０の具体的な形状や構造を問わない。例えば、図１等には前後両端に切削刃２１をもつ両刃の刃物２０を示したが、前記図８（ａ）に示した片刃式の刃物２０を工具本体に装着する場合にも本発明の適用が可能である。
【００４９】
(2) 止めねじ２６と工具本体１１との係合構造も特に問わない。例えば、止めねじ２６をその軸方向に全域にわたって雄ねじを有する構造とし、工具本体１１の外周面に前記雄ねじが螺合可能なねじ孔を設けるようにしてもよい。
【００５０】
(3) 取付孔２４ｂ内への回り止めピン２８の固定手段は圧入に限らない。例えば接着剤を用いてもよいし、前記取付孔２４ｂをねじ孔とし、これに螺合可能な雄ねじを回り止めピン２８に形成するようにしてもよい。このようなねじ構造で仮にそのねじが緩んでも、これに伴う回り止めピン２８の変位方向は内方に突出する方向であるため、この回り止めピン２８と回り止め係合部１１ｅとの係合が外れる心配はない。
【００５１】
(4) 回り止め係合部１１ｅの形状は、前記のような平面状のものに限らず、例えば回り止めピン２８が軸方向に進入可能な溝状にしてもよい。ただし、前記のような平面状の回り止め係合部１１ｅとすれば、形成容易な形状としながら確実な回り止めができる。
【００５２】
【発明の効果】
以上のように本発明は、刃物の筒状取付部分にねじ孔を設け、このねじ孔に螺合される止めねじと係合するねじ係合部を工具本体に設けるとともに、このねじ孔と対向する位置に取付孔を設けてこれに回り止め部材を取付け、この回り止め部材と工具本体との係合によって両者の相対回転が規制されるように構成し、かつ、その規制位置で前記ねじ孔とねじ係合部との位置が合致するようにした孔開け工具を製造するための方法であって、前記刃物の筒状取付部分にこの筒状取付部分を径方向に貫通するねじ孔を設け、このねじ孔に別の孔開け工具を挿通することにより前記筒状取付部分の内周面に取付孔を設け、この取付孔内に前記ねじ孔を通じて回り止め部材を挿入し、固定するものであるので、工具本体に対する刃物の着脱作業を簡単にし、かつ、その装着状態での信頼性を高めることが可能な孔開け工具を簡単に製造することができる効果がある。
【図面の簡単な説明】
【図１】本発明の実施の形態にかかる孔開け工具の一部断面正面図である。
【図２】前記孔開け工具における工具本体の一部断面正面図である。
【図３】（ａ）は前記孔開け工具における刃物の側面図、（ｂ）は同刃物の断面正面図である。
【図４】（ａ）は前記孔開け工具の要部を示す断面正面図、（ｂ）は（ａ）のＡ−Ａ線断面図である。
【図５】（ａ）（ｂ）は前記孔開け工具の刃物の製造工程を示す断面正面図である。
【図６】（ａ）は頭部付の回り止めピンを用いた孔開け工具の要部を示す断面正面図、（ｂ）は（ａ）のＣ−Ｃ線断面図である。
【図７】（ａ）は前記頭部付の回り止めピンと取付孔とを示す断面斜視図、（ｂ）は同取付孔への回り止めピンの挿入が完了した状態を示す断面図である。
【図８】（ａ）は従来の孔開け工具の一例を示す断面正面図、（ｂ）は（ａ）のＢ−Ｂ線断面図である。
【符号の説明】
１１工具本体
１１ａ駆動連結部
１１ｅ回り止め係合部
１１ｔテーパー孔（ねじ係合部）
１２センタードリル
２０刃物
２１切削刃
２４筒状取付部分
２４ａねじ孔
２４ｂ取付孔
２６止めねじ
２６ｔ止めねじのテーパー部
２８回り止めピン（回り止め部材）
２８ａ回り止めピンの頭部
３４ドリル（別の孔開け工具）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drilling tool for drilling holes in walls, ceilings, and other workpieces, and a method of manufacturing the drilling tool.
[0002]
[Prior art]
Conventionally, as the drilling tool as described above, there is a cutter having a plurality of cutting blades at the end of a substantially cylindrical body, and the tool main body is a rotary drive machine in a state where the cutter is mounted on the tool main body. It is generally known that the entire tool is integrally rotated by being connected to a drive source such as the above. Furthermore, in recent years, it has become possible to mount a plurality of types of cutters having different machining diameters on a single tool body, or to use a cutter provided with the above-mentioned cutting blades at both ends of the cutter axial direction in order to extend the life of the cutter. In order to do so, a device for making the blade detachable from the tool body has been studied.
[0003]
An example of the structure is shown in FIGS. This tool has a tool main body 80 connected to a drive source (not shown), and a center drill 84 for center positioning is detachably attached to a front end portion 82 thereof, and a cutter 90 is provided outside the front end portion 82. Is detachably mounted.
[0004]
The cutter 90 has a cylindrical body 91, and a plurality of cutting blades 92 are fixed to the tip of the cutter 90 in the circumferential direction, while the base of the cutter 90 is fixed to the tip 82 of the tool body 80. It is set as the cylindrical attachment part 94 fitted outside. The cylindrical mounting portion 94 is provided with two screw holes 94a penetrating in the radial direction at intervals of 180 °, and a set screw 96 can be screwed into each screw hole 94a. On the other hand, on the outer peripheral surface of the tip end portion 82 of the tool main body, two anti-rotation engaging portions 82a are formed by cutting out two portions in a flat shape, and the set screws 96 are respectively formed on the anti-rotation engaging portions 82a. As a result, the relative rotation of the blade 90 with respect to the tool main body 80 is restricted, and the two are integrally rotated.
[0005]
The procedure for using this drilling tool is as follows.
[0006]
{Circle around (1)} A set screw 96 is inserted into each screw hole 94a of the blade 90 in advance. At that time, each set screw 96 is positioned to the outside in the radial direction to some extent so that its end portion does not protrude inward from the inner peripheral surface of the cylindrical mounting portion 94.
[0007]
{Circle around (2)} The cylindrical mounting portion 94 of the blade 90 is fitted to the outside of the tool main body tip portion 82. Then, the relative angle between the tool main body 80 and the blade 90 is adjusted so that the positions of the anti-rotation engaging portion 82a of the tip end portion 82 and the set screw 96 coincide with each other, and then each set screw 96 is tightened in the tightening direction. Rotate to displace inward and engage its end with each anti-rotation engaging portion 82a (completed attachment of the blade 90 to the tool body 80).
[0008]
(3) The tool body 80 is connected to an unillustrated rotary drive to rotate the entire drilling tool. In this state, first, the center drill 84 is pressed against the construction surface to center the machining hole (center positioning), and then the cutting blade 92 of the blade 90 cuts the periphery thereof, so that it is substantially the same as the blade 90. A hole of diameter is drilled.
[0009]
[Problems to be solved by the invention]
In the drilling tool, after the cylindrical mounting portion 94 of the cutter 90 is fitted on the tool body tip 82, the circumferential position of the set screw 96 and the circumferential position of the anti-rotation engaging portion 82a are matched. Although the positioning operation in the direction is necessary, in such an external fitting state, the rotation preventing engagement portion 82a is hidden inside the cylindrical mounting portion 94 and cannot be seen from the outside, so that the positioning operation is not easy. In addition, both the set screws 96 need to be rotated separately after positioning, which is very laborious.
[0010]
Further, since the relative rotation of the blade 90 with respect to the tool body 80 is all regulated by the engagement between the set screw 96 and the tool body 80, both set screws 96 are loosened due to vibration during use, etc. In the case of separation from the part 82a, there is no restriction on the relative rotation, torque transmission from the tool body 80 to the blade 90 becomes impossible, and construction must be interrupted.
[0011]
Furthermore, when manufacturing this tool, it is necessary to provide two screw holes 94a in the cylindrical mounting portion 94, which requires labor.
[0012]
In view of such circumstances, and an object thereof is to provide a method for detaching operations of the cutter to the tool body to easily manufacture a simple, high have perforating tool also its mounting reliability.
[0013]
[Means for Solving the Problems]
As means for solving the above-mentioned problems, the present invention has a tool main body connected to a drive source and a cylindrical mounting portion that can be fitted to the outside of the tool main body, and the tool main body in the fitted state. and a cutter fixed to the tool body to rotate integrally, a screw hole penetrating the cylindrical mounting portion in the radial direction provided in the cylindrical mounting portion, the inner peripheral surface of the cylindrical mounting portion In the mounting hole, a mounting hole is provided at a position facing the screw hole, and the anti-rotation member is mounted in the mounting hole in a state where the anti-rotation member protrudes inward from the inner peripheral surface of the cylindrical mounting portion. And a non-rotating engaging portion for restricting relative rotation between the tool body and the cutter by engaging with the protruding portion of the non-rotating member on the outer peripheral surface to which the cylindrical mounting portion is fitted, and Angular position where the joint and the detent member are engaged In the threaded hole and located in matching positions, a method for manufacturing a set screw and engaging threaded engagement portion and the hole drilled tool provided to be engaged to be screwed through to the screw hole, wherein A screw hole that penetrates the cylindrical mounting portion in the radial direction is provided in the cylindrical mounting portion of the blade, and another mounting tool is inserted into the screw hole so that the mounting hole is formed on the inner peripheral surface of the cylindrical mounting portion. A rotation preventing member is inserted into the mounting hole through the screw hole and fixed .
[0014]
According to the drilling tool manufactured by this method, if the cylindrical mounting portion of the cutter is fitted to the outer peripheral surface of the tool main body at the relative angular position where the anti-rotation member and the anti-rotation engagement portion are engaged, Since the position of the screw hole on the cylindrical mounting portion side and the position of the screw engaging portion on the outer peripheral surface side of the tool body automatically match, the set screw is advanced inward in the screw hole as it is, By engaging with the joint part, it is possible to complete the attachment of the blade to the tool body. Therefore, it is easier to align the tool body and the blade in the circumferential direction several times compared to conventional tools, and both the set screw and the non-rotating member can be operated only by rotating a single set screw. Thus, the blade can be reliably fixed to the tool body so as not to rotate relative to the tool body.
[0015]
In addition, the cutter is prevented from being rotated only by a set screw as in the prior art, and the cutter is prevented from being rotated by a locking member mounted in a mounting hole formed on the inner peripheral surface of the cylindrical mounting portion. Even if the set screw is loosened due to vibration of the tool or the like, the relative rotation restriction by the rotation preventing member is continued. Therefore, it is not necessary to interrupt the construction, and the reliability in the mounted state is high.
[0016]
And according to the said method , the said drilling tool can be manufactured easily by providing the said screw hole and the attachment hole in the position which mutually opposes. That is, a screw hole that penetrates the cylindrical attachment portion in the radial direction is provided in the cylindrical attachment portion of the cutter, and another drilling tool is inserted into the screw hole, thereby forming an inner peripheral surface of the cylindrical attachment portion. Even though the inner space of the cylindrical mounting portion is rather narrow, the screw hole formed first is skillfully achieved by providing a mounting hole and inserting and fixing the anti-rotation member through the screw hole into the mounting hole. Utilizing this, the mounting hole and the rotation preventing member can be easily provided on the inner peripheral surface of the cylindrical mounting portion.
[0017]
Here, as a means for determining the protrusion amount of the rotation prevention member from the inner peripheral surface of the cylindrical attachment portion, the attachment hole is provided with a bottom, and the rotation prevention member is inserted into the attachment hole until it hits the bottom. Alternatively, a head having a cross-sectional shape larger than that of the insertion end is formed on the detent member, and the head is inserted into the mounting hole up to a depth at which the head hits the inner peripheral surface of the cylindrical mounting portion. An anti-rotation member may be inserted. In the latter case, since the head dimension of the anti-rotation member becomes the protrusion amount of the anti-rotation member as it is, there is an advantage that the setting of the protrusion amount is very easy.
[0018]
Further, the means for attaching the anti-rotation member into the attachment hole is not limited, and simple press-fitting may be used, or the anti-rotation member may be fixed by an adhesive or other means.
[0019]
On the other hand, the anti-rotation engaging portion on the tool body side can be easily formed by cutting out a part of the outer peripheral surface of the tool body.
[0020]
The present invention can be applied to manufacture of various drilling tools in which a tool is detachably mounted on a tool body. Specifically, the tool body is provided with a center drill at the tip thereof, and the cutter has a substantially cylindrical shape that covers the periphery of the center drill in a coaxial state with a cutting blade at the tip. It is particularly suitable for the manufacture of tools having
[0021]
For example, in the case where the cutter has the cutting blades at both ends thereof and the cylindrical mounting portion at the intermediate portion, it is possible to selectively use cutting at both ends of the cutter by simplifying the attaching / detaching operation between the tool body and the cutter. It can be done easily.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described with reference to the drawings.
[0023]
The drilling tool shown here includes a tool body 11 shown in FIGS. 1 and 2 and a blade 20 shown in FIGS. 1 and 3.
[0024]
A drive connecting portion 11a connected to a rotary drive machine (not shown) is formed at the rear portion of the tool body 11, and a center drill (drill bit) 12 is attached to the front portion. Specifically, as shown in FIG. 2, the tool body 11 has a drill mounting hole 11b that opens forward along the central axis thereof, and a screw hole that leads from the outer peripheral surface of the tool body to the deep part of the drill mounting hole 11b. 11c is formed. On the other hand, a drill blade 12a is formed in the front part of the center drill 12, a round shaft-shaped shank part 12b is formed in the rear part, and a notch 12c in which a part in the circumferential direction is cut out is formed on the outer peripheral surface of the rear end part. With the shank portion 12b inserted into the drill mounting hole 11b, the center drill 12 is attached to the tool body 11 by tightening the set screw 14 in the screw hole 11c and engaging with the notch 12c. It is supposed to be fixed.
[0025]
A spiral spring 18 for removing chips is mounted around the drill blade 12a of the center drill 12.
[0026]
The front end portion of the tool body 11 has a smaller diameter than the rear portion, and a step portion 11d is formed at the boundary. Further, a taper hole 11t that penetrates the front end portion in the radial direction is provided at the front end portion, and a detent engagement portion having a shape in which the outer peripheral surface is cut out in a plane on the back side (opposite side) of the taper hole 11t. 11e is formed. The tapered hole 11t has a tapered inner peripheral surface in a direction of reducing the diameter toward the radially inner side.
[0027]
The blade 20 has a substantially cylindrical shape that is symmetrical in the longitudinal direction. A plurality of cutting blades 21 arranged in the circumferential direction are provided at both front and rear ends, and through holes 22 for discharging chips are provided at appropriate positions on the inner side. The middle portion of the cutter 20 in the front-rear direction is a cylindrical mounting portion 24 having a larger wall thickness (the outer diameter is larger and the inner diameter is smaller) than the other portions, and the front end portion of the tool body 11 can be fitted inside thereof. That is, the cylindrical attachment portion 24 can be fitted to the outside of the front end portion of the tool body 11. And the axial positioning of the cutter 20 with respect to the tool main body 11 is made by the contact between the rear end of the inner peripheral portion of the cylindrical mounting portion 24 and the step portion 11d of the tool main body 11.
[0028]
The cylindrical mounting portion 24 is provided with a screw hole 24a penetrating in the radial direction, and a set screw 26 is screwed into the screw hole 24a. The set screw 26 has a male screw 26a that can be screwed into the screw hole 24a on the outer peripheral surface thereof, and a recess 26b for inserting the wrench 30 is provided on the head. An inner end portion of the set screw 26 is a tapered portion 26t having a taper angle substantially equal to that of the tapered hole 11t, and the tapered portion 26t is press-fitted into the tapered hole 11t. The tool body 11 is pulled toward the front end side, and the stepped portion 11d is pressed against the inner peripheral portion of the rear end of the cylindrical mounting portion 24, so that the blade 20 is fixed to the tool body 11 and the screw hole 24a and the taper. A relative positional relationship in the axial direction with the hole 11t is set.
[0029]
On the inner peripheral surface of the cylindrical mounting portion 24, a bottomed circular mounting hole 24b is provided at a position on the extension line of the screw hole 24a (that is, a position facing the screw hole 24a). An anti-rotation pin (anti-rotation member) 28 is press-fitted and fixed. The head of the detent pin 28 projects slightly inward from the inner peripheral surface of the cylindrical projecting portion 24, and the projecting head engages with the detent engaging portion 11 e of the tool body 11. The relative angular position of the blade 20 with respect to the tool body 11 is regulated, and both the position of the tapered hole 11t and the position of the screw hole 24a are matched in the circumferential direction at the regulated position. The position is set.
[0030]
In FIG. 1 and the like, reference numeral 16 denotes a blade cover made of rubber or the like provided in a bowl shape on the outer peripheral surface of the tool body 11, and the cutting blade 21 on the unused side (rear end side) is cut by the blade cover 16. Exposure to the worker side is prevented.
[0031]
Next, an example of how to use this drilling tool will be described.
[0032]
(1) A set screw 26 is screwed into the screw hole 24a in advance. The set screw 26 is set so that the inner end of the set screw 26 does not protrude inward from the inner peripheral surface of the cylindrical protruding portion 24. The position of the screw 26 is reserved from the outside in the radial direction.
[0033]
(2) The cylindrical mounting portion 24 is fitted to the outside of the front end portion of the tool body 11 at an angular position where the rotation prevention pin 28 and the rotation prevention engagement portion 11e are engaged. Thereby, the taper hole 11t on the tool body 11 side and the screw hole 24a on the cylindrical mounting portion 24 side match. Since this fitting can be performed only at an angular position where the detent pin 28 and the detent engaging portion 11e are engaged, if the fitting is performed, the tapered hole 11t and the cylindrical mounting portion 24 are automatically positioned. Will be matched. Therefore, it is not necessary to perform the alignment work specially. In addition, the relative rotation of the blade 20 with respect to the tool body 11 is reliably regulated by this fitting.
[0034]
(3) Insert the wrench 30 into the recess 26b of the set screw 26, and rotate the set screw 26 to tighten the set screw 26 inward. As a result, the outer peripheral surface of the set screw taper portion 26t and the inner peripheral surface of the taper hole 11t of the tool body 11 are pressed against each other on the front side (left side in FIG. 4A), and the tool body 11 is pulled forward by the taper action. It is done. That is, the step portion 11 d of the tool main body 11 is pressed against the inner peripheral portion of the rear end of the cylindrical attachment portion 24, whereby the blade 20 is completely fixed to the tool main body 11. Accordingly, the blade 20 can be fixed only by rotating the single set screw 26.
[0035]
(4) The drive connecting portion 11a of the tool body 11 is connected to a rotary drive machine (not shown) to drive the entire tool at high speed. In this state, the center position of the machining hole is first determined by pressing the drill blade 12a of the center drill 12 against the construction surface, and then the cutting blade 21 of the blade 20 is pressed against the construction surface. Is done.
[0036]
Here, even if the set screw 26 is loosened due to vibration during construction or the like, the relative rotation of the blade 20 with respect to the tool body 11 continues to be restricted by the engagement of the anti-rotation pin 28 and the anti-rotation engagement portion 11e (ie, the tool). Since torque transmission from the main body 11 to the blade 20 can be continued), the construction can be continued without any trouble. The set screw 26 may be retightened after the construction is finished.
[0037]
(5) For example, when it is desired to remove the blade 20 for the purpose of exchanging the blade 20 or turning the blade 20 in the reverse direction (that is, using the cutting blade 21 on the opposite side), the set screw 26 is loosened (the set screw 26 has a diameter). The taper portion 26t may be retracted from the taper hole 11t by turning in the direction of displacement outward. Thereby, the cylindrical attachment part 24 can be easily removed forward from the front end of the tool body 11.
[0038]
As described above, according to the drilling tool according to this embodiment, the blade 20 can be attached and detached by a few steps easier than the conventional tool shown in FIG. Reliability is also greatly improved. And the attachment structure of the blade 20 in this drilling tool can be easily manufactured by the following method, for example.
[0039]
(1) A screw hole 24 a is provided at an appropriate position of the cylindrical mounting portion 24.
[0040]
(2) A bush 32 as shown in FIG. 5A, for example, is inserted into the screw hole 24a from the outside, and the tip of the bush 32 abuts against the inner peripheral surface facing the screw hole 24a.
[0041]
{Circle around (3)} A drill 34 shown in FIG. 5A is inserted inside the bush 32, and a bottomed mounting hole 24 b is formed on the inner peripheral surface by the tip of the drill 34.
[0042]
{Circle around (4)} The drill 34 is removed from the bush 32, and then the rotation prevention pin 28 is fitted into the mounting hole 24 b through the bush 32. In the case of press-fitting, pressure is applied to the detent pin 28 from above by, for example, pushing a push rod into the bush 32 (see the arrow in FIG. 5B).
[0043]
That is, in this drilling tool, the mounting hole 24b is provided at a position facing the screw hole 24a, and the anti-rotation pin 28 is mounted on the mounting hole 24b. Therefore, by effectively using the screw hole 24a provided first, Even in a narrow space in the cylindrical mounting portion 24, the mounting hole 24b and the rotation stopper pin 28 can be provided without difficulty on the inner peripheral surface thereof.
[0044]
Incidentally, in the structure shown in FIGS. 1 to 5, in order to accurately determine the amount of protrusion of the locking pin 28 from the inner peripheral surface of the cylindrical mounting portion 24, the depth dimension of the bottomed mounting hole 24b is set to the above-mentioned depth. If the pin 28 is inserted into the mounting hole 24b to a depth where the detent pin 28 abuts against the bottom of the mounting hole 24b after adjusting to the dimension obtained by subtracting the target protrusion amount from the entire length of the locking pin 28. Good. However, it is not easy to accurately match the depth dimension of the mounting hole 24b with the target dimension, and errors are likely to occur.
[0045]
On the other hand, as shown in FIGS. 6 and 7, the head (having a large-diameter circle in the example) having a larger cross-sectional shape than the insertion end (the lower end in FIGS. 6 and 7) of the rotation prevention pin 28 in advance If the portion 28a is formed and the height dimension h of the head portion 28a is adjusted to the target protrusion amount, the detent pin 28 is attached to a depth where the head portion 28a hits the inner peripheral surface of the cylindrical attachment portion 24. As shown in FIG. 7 (b), just by inserting into the hole 24b, regardless of the depth dimension d of the mounting hole 24b (extremely the mounting hole 24b penetrates the cylindrical mounting portion 24, In addition, it is possible to make the protrusion amount of the rotation prevention pin 28 coincide with the target protrusion amount, that is, the height dimension h of the head portion 28a. Thus, it is much easier to match the height dimension of the head portion 28a of the locking pin 28 to the target protrusion amount than to match the depth dimension of the mounting hole 24b to the target dimension.
[0046]
Here, the cross-sectional shape of the main body of the detent pin 28 and its head 28a is not necessarily limited to a circle. Regardless of how the shape is set, if the cross-sectional shape of the head portion 28a is made larger than the insertion end portion so that the head portion 28a always comes into contact with the inner peripheral surface of the cylindrical mounting portion 24, then The effect of can be obtained.
[0047]
In addition, this invention can also take the following embodiment as an example.
[0048]
(1) In this invention, the specific shape and structure of the blade 20 are not ask | required. For example, FIG. 1 and the like show a double-edged blade 20 having cutting blades 21 at both front and rear ends, but the present invention also applies to the case where the single-edged blade 20 shown in FIG. Applicable.
[0049]
(2) The engagement structure between the set screw 26 and the tool body 11 is not particularly limited. For example, the set screw 26 may be configured to have a male screw over the entire region in the axial direction, and a screw hole into which the male screw can be screwed may be provided on the outer peripheral surface of the tool body 11.
[0050]
(3) The means for fixing the rotation prevention pin 28 in the mounting hole 24b is not limited to press-fitting. For example, an adhesive may be used, or the mounting hole 24 b may be a screw hole, and a male screw that can be screwed into the mounting hole 24 b may be formed on the anti-rotation pin 28. Even if the screw is loosened with such a screw structure, the displacement direction of the rotation-preventing pin 28 is the direction projecting inward, so the engagement between the rotation-preventing pin 28 and the rotation-stop engaging portion 11e. There is no worry about losing.
[0051]
(4) The shape of the anti-rotation engaging portion 11e is not limited to the planar shape as described above, and may be a groove shape in which the anti-rotation pin 28 can enter in the axial direction, for example. However, if the planar anti-rotation engaging portion 11e is used as described above, the anti-rotation can be reliably performed while the shape is easy to form.
[0052]
【The invention's effect】
As described above, according to the present invention, a screw hole is provided in the cylindrical mounting portion of the cutter, a screw engaging portion that engages with a set screw that is screwed into the screw hole is provided in the tool body, and the screw hole is opposed to the screw hole. An anti-rotation member is provided at a position where the anti-rotation member is attached, and the relative rotation of the anti-rotation member and the tool body is restricted by the engagement of the anti-rotation member and the screw hole at the restriction position. Is a method for manufacturing a drilling tool in which the positions of the screw engaging portion and the screw engaging portion coincide with each other, wherein the cylindrical mounting portion of the cutter is provided with a screw hole that penetrates the cylindrical mounting portion in the radial direction. By inserting another drilling tool into this screw hole, a mounting hole is provided on the inner peripheral surface of the cylindrical mounting portion, and a non-rotating member is inserted into the mounting hole through the screw hole and fixed . Easy to attach / detach the tool to / from the tool body And, and, there is an effect that it is possible to simply manufacture the perforating tool capable of enhancing the reliability in its mounted state.
[Brief description of the drawings]
FIG. 1 is a partial sectional front view of a drilling tool according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional front view of a tool body in the drilling tool.
FIG. 3A is a side view of a cutter in the drilling tool, and FIG. 3B is a sectional front view of the cutter.
4A is a cross-sectional front view showing the main part of the drilling tool, and FIG. 4B is a cross-sectional view taken along line AA in FIG.
FIGS. 5A and 5B are cross-sectional front views showing a manufacturing process of the cutter of the drilling tool. FIGS.
6A is a cross-sectional front view showing a main part of a drilling tool using a detent pin with a head, and FIG. 6B is a cross-sectional view taken along the line CC of FIG.
7A is a cross-sectional perspective view showing the non-rotating pin with the head and the mounting hole, and FIG. 7B is a cross-sectional view showing a state where the insertion of the non-rotating pin into the mounting hole is completed.
8A is a sectional front view showing an example of a conventional drilling tool, and FIG. 8B is a sectional view taken along line BB in FIG. 8A.
[Explanation of symbols]
11 Tool body 11a Drive connecting portion 11e Anti-rotation engaging portion 11t Taper hole (screw engaging portion)
12 Center drill 20 Cutting tool 21 Cutting blade 24 Cylindrical mounting part 24a Screw hole 24b Mounting hole 26 Set screw 26t Taper part 28 of set screw Non-rotating pin (anti-rotating member)
28a Non-rotating pin head 34 Drill (another drilling tool)

Claims

A tool body connected to the drive source and a cylindrical mounting portion that can be fitted to the outside of the tool body, and fixed to the tool body so as to rotate integrally with the tool body in the fitted state. Provided with a blade, provided in the cylindrical mounting portion with a screw hole that penetrates the cylindrical mounting portion in the radial direction, and provided with a mounting hole at a position facing the screw hole on the inner peripheral surface of the cylindrical mounting portion, In the mounting hole, the anti-rotation member is attached in a state where the anti-rotation member protrudes inward from the inner peripheral surface of the cylindrical attachment portion, while the cylindrical attachment portion is fitted to the outer peripheral surface of the tool body. An anti-rotation engaging portion for restricting relative rotation between the tool main body and the cutter by engaging with the protrusion of the anti-rotation member, and an angle at which the anti-rotation engaging portion and the anti-rotation member are engaged. At a position that matches the screw hole To a set screw engaged with the screw engagement portion and the hole-forming process for producing a tool provided by being screwed inserted,
Provided with a screw hole that penetrates the cylindrical mounting portion in the radial direction in the cylindrical mounting portion of the cutter,
By attaching another drilling tool to this screw hole, an attachment hole is provided on the inner peripheral surface of the cylindrical attachment part,
A method for manufacturing a drilling tool , comprising: inserting and fixing a locking member into the mounting hole through the screw hole .

The method of manufacturing a drilling tool according to claim 1, method for producing a drilling tool, characterized in that the detent engaging portion formed by notching a part of the outer peripheral surface of the tool body.

3. The method for manufacturing a drilling tool according to claim 1 or 2, wherein the tool body is provided with a center drill at a tip portion thereof, and the blade is a substantially cylindrical covering the periphery of the center drill coaxially therewith. A method for manufacturing a drilling tool , characterized in that it has a shape and has a cutting blade at its tip.

The manufacturing method of claim 3, wherein the punching tool, the tool has the cutting edge at its opposite ends, holes drilled production method of a tool and having the tubular mounting portion to the intermediate portion.

The method for manufacturing a drilling tool according to any one of claims 1 to 4, wherein the mounting hole has a bottom, and the detent member is inserted into the mounting hole until it hits the bottom. Tool manufacturing method .

In the manufacturing method of the drilling tool in any one of Claims 1-4, the head with a larger cross-sectional shape is formed in the said rotation stop member than the insertion end part, This head is the said cylindrical attachment part. A method for manufacturing a drilling tool , comprising inserting the anti-rotation member into a mounting hole to a depth corresponding to an inner peripheral surface.

The method for manufacturing a drilling tool according to any one of claims 1 to 6 , wherein the detent member is press-fitted into the mounting hole.