JP4287533B2

JP4287533B2 - Tailstock fixing mechanism

Info

Publication number: JP4287533B2
Application number: JP08288399A
Authority: JP
Inventors: 祥弘羽田野; 竜司上林
Original assignee: Okuma Corp
Current assignee: Okuma Corp
Priority date: 1998-03-26
Filing date: 1999-03-26
Publication date: 2009-07-01
Anticipated expiration: 2019-03-26
Also published as: JPH11333602A

Description

【０００１】
【発明の属する技術分野】
本発明は工作機械のセンタワークに使用される心押台の固定機構に関するものである。
【０００２】
【従来技術】
従来技術を示す図５は旋盤における心押台の配置例を示す。心押台１０１はベッド１０２の摺動面１０３上をチャック１０４と同心に移動可能に設けられている。ワーク１０５の長さに応じて心押台１０１を移動させた後心押台１０１を摺動面１０３に固定する。その際ボルト１０６をスパナで締める方法や心押台１０１の向こう側に位置し作業者の機台操作上障害にならない位置に図示しないクランプレバーと偏心軸とを設けて摺動面１０３にクランプする方法がある。
【０００３】
又図６（ａ）（ｂ）に固定機構の他の従来例を示す。
心押台１０１が傾斜する摺動面１１１上に載架されている場合である。固定用のボルト１０６を直接スパナで固定方向に回転させるとボルト６の下部で係合する固定板１１２を持ち上げ心押台１０１の下面と固定板１１２の間に摺動面１１１を挟持し心押台１０１を固定している。ナット１１３はボルト１０６に螺合させた後ピン１１４でゆるみ止めがされているので固定板１１２が落下することがない。
【０００４】
又ボルト１０６の固定板１１２との係合部分を揺動支点とし、ボルト１０６の頭部に該ボルトの軸線に直角に貫通穴を設け、前記貫通穴に嵌入する部分を偏心円筒形状とする操作用の横軸を設ける場合がある。
【０００５】
【発明が解決しようとする課題】
図５に示す旋盤ではスパナ又はクランプレバーを人手で操作することが多い。機械の高生産性を追求する目的と安全上及び作業環境上の問題から殆どの機械構成部分はカバーで覆われている。そのため心押台１０１クランプ動作を行うに先立ち、前面窓１０７又は側面窓１０８を開いて操作する必要がある。固定用ボルト１０６を２個所以上に設けられていると時間のかかる作業となる。
【０００６】
更に固定・ゆるめの作業は繰り返されるのでボルト１０６のねじ部に緊定反力が直接加わり長期使用に対しねじ部が摩耗し固定の安定性が減少する。心押台１０１が大形化した場合には大きな固定力が必要となるが、手締め作業で直接ボルト１０６を操作する場合十分な固定力を得るのが困難となる。
【０００７】
又図６（ａ）（ｂ）に示す傾斜した摺動面１１１上に載架された心押台１０１の場合摺動面はＹ面１１６でありＸ軸方向の案内面のＸ面１１７には心押台１０１の凸起部１１５が当接し、心押台１０１が案内されている。この場合ボルト１０６で心押台１０１を固定したとき心押台１０１が常にＸ面に当接した状態で固定されるとは限らないのでＸ軸方向の位置が確定されないという問題が生ずる。
【０００８】
本発明は従来技術の有するこのような問題に鑑みなされたものであり、その目的とするところは平面又は傾斜面に載架された心押台を小さな操作力でもって精度良く大きな緊定力で摺動面に固定できる機構を提供しようとするものである。
【０００９】
【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の心押台固定機構の発明は、心押台を摺動面に固定する機構であって、摺動面の裏面に当接して心押台を固定する固定板と、前記固定板を引上げ可能に軸端に前記固定板との係合部を有し互いに平行に配設された複数の縦軸と、前記複数の縦軸に直角方向に設けられ複数のねじ部を有する横軸と、複数の前記縦軸の各々の上部軸端に固着され下面にテーパ面を有する第１の駒と、前記横軸のねじ部に各々螺合し上面にテーパ面を有して前記第１の駒と各々テーパ面で係合する第２の駒とからなり前記横軸を回転させることにより縦軸を引上げることで心押台を固定するようにしたものである。
【００１０】
請求項１の発明は、横軸に加える回転操作力が少なくとも駒のテーパ係合部により緊定力が拡大されるので強固な心押台の固定が可能となる。横軸に螺切されたねじに加わる力も少なくて良いのでねじの摩耗も少なく長期間に亘って安定した固定が期待できる。
【００１１】
また請求項２の心押台固定機構の発明は、前記横軸のねじ部が２個所に設けられ且つ互いに逆方向のねじに形成されているものである。
横軸と横軸とねじで係合する駒部材５ａ，５ｂ間を互いに逆方向のねじで形成しているので、横軸軸端部の１個所の軽快な操作により複数個所で心押台を強固に固定することが可能である。
【００１２】
また、請求項３の心押台固定機構の発明は、心押台を摺動面に固定する機構であって、心押台下面とで摺動面を挟持する固定板を引上げる縦軸に係合し下面にテーパ面を有する第１の駒と上面に前記テーパ面と係合し相対移動により挟持力を増大させる第２の駒を設け、該第２の駒を前記摺動面に平行な方向に移動させる移動手段を設け、前記縦軸を前記摺動面に対し傾斜させ且つ傾斜方向に上下移動自在とし、前記固定板に前記縦軸が引上げられたときに前記摺動面の角部の端面に当接する段付部を設けてなり、前記移動手段で前記第２の駒を移動させることにより前記縦軸を介して固定板引上げ時に摺動面の対向前記角部の少なくとも一方の角部に引き上げ力の分力を作用させて固定するようにしたものである。
【００１３】
傾斜した摺動面上の心押台を、安定してベースの摺動面上に固定するために傾斜した摺動面の上面・下面を上下方向から挟持するだけでなく、縦軸と傾斜した摺動面との関係で生ずる引上げ時の分力を利用して、対向する摺動面の角部で心押台のＸ方向の位置固定を安定したものとすることができる。
【００１４】
また、請求項４の心押台固定機構の発明は、心押台を摺動面に固定する機構であって、心押台下面とで摺動面を挟持する固定板を引き上げる縦軸に係合し下面にテーパ面を有する第１の駒と上面に前記テーパ面と係合し相対移動により挟持力を増大させる第２の駒を設け、該第２の駒を前記摺動面に平行な方向に移動させる移動手段を設け、前記固定板に摺動面と当接する一方に当接段付部と最深部をテーパ面を有する切欠部とを形成し他方に前記摺動面に当接する段付部を形成すると共に前記切欠部に嵌装され前記切欠部の最深部のテーパ面に当接し前記摺動面の内側端面と当接する第３の駒を設け、前記移動手段で前記第２の駒を移動させることにより前記縦軸を引上げた時に前記第３の駒のテーパ面で生ずる分力を前記摺動面の下面と側面に伝えて心押台を固定するようにしたものである。
【００１５】
傾斜した摺動面上の心押台を、安定してベースの摺動面上に固定するために傾斜した摺動面の上面下面を上下方向から挟持するだけでなく固定板に設けた第３駒のテーパ面の作用を利用して心押台のＸ方向分力を支えるようにしたものであり、本構造より安定した固定が期待できる。
【００１７】
また、請求項５の心押台固定機構の発明は、心押台を摺動面に固定する機構であって、前記摺動面の裏面に当接する楔形状の楔状板と、前記心押台近傍に前記摺動面に載置され前記楔状板と一体に前記心押台の進退方向に移動自在に設けられたブロックと、該ブロックと前記楔状板を前記摺動面に固定するクランプ部材と、前記楔状板の下面のテーパ面に当接し前記摺動面に載置された心押台の下面に一体固着した裏板と、前記ブロックと前記心押台とを接近離間させる調整部材とを設けてなり、該調整部材を操作して楔状板を心押台の進退方向に移動させ楔効果を操作して後クランプ部材で固定するようにしたものである。
【００１８】
【発明の実施の形態】
以下本発明の実施の形態を図面にもとづいて説明する。
図１は本発明に係る心押台の固定機構の断面説明図（実施例１）、図２，図３は心押台が傾斜した摺動面に固定される場合の断面図（実施例２，実施例３）、図４は心押台を摺動面下面に当接する楔状板で固定する楔状部材、ジャッキボルト、クランプ部材の断面図（実施例４）である。
【００１９】
〔実施例１〕
図１はベッド９上の水平な摺動面上に載架された心押台１に設けた心押台固定構造の実施例である。移動手段である横軸２の軸端の操作部３を直接操作する場合又は軸端に図示しない操作レバーを取着し作業性良く心押台１を固定することができる。
【００２０】
図１において、心押台１は水平の摺動面を有するベッド９上に載架されている。縦軸７，１１を降下させると固定板８も降下しベッド９を挟持している状態を取り除く。心押台１はＺ軸方向に手動で移動可能に設けられている。センタワーク時にはワークの軸方向の長さに応じ主軸台のチャックと心押台の心押軸間の距離を調節するため、心押台を頻繁に移動し固定する必要がある。
特に心押台が大形の機械であったり傾斜した摺動面上に心押台１がある場合に強固に人手でベッド９に固定する構造を当該心押台に構成する必要がある。
【００２１】
本発明の心押台固定機構の構成を図１にもとづき説明する。心押台１は縦軸７，１１の上昇により縦軸の軸端下部に螺合し回り止めピン１２でゆるみ止めが施されたナット１３に当接して該縦軸のそれぞれの下部軸端に係合する固定板８とでベッド９の摺動面に固定される。縦軸７，１１の上下方向の移動を生じさせるため縦軸７，１１に直交する横軸２との間にテーパ面で係合する楔状部材である駒部材５ａ，５ｂ，６ａ，６ｂを設け、前記駒部材５ａ，５ｂ，６ａ，６ｂの相対変位により横軸２の回転を両縦軸７，１１の上下方向移動に変換させている。
【００２２】
心押台の外部であって手で回転操作可能の位置に突出させベッド９の摺動面に平行に設けた軸の軸端に操作部３を有し軸中央部から軸端の二方向に右ねじ、左ねじを刻設した横軸２と、貫通した右ねじ又は左ねじを有して上面にテーパ面を有する駒部材５ａ，５ｂがガイド穴２２に嵌装され横軸２のねじ部とテーパ面をそれぞれ反対方向に向けて螺合しており、駒部材５ａ，５ｂのテーパ面の上面に当接するテーパ面を有する駒部材６ａ，６ｂが第１，第２縦軸７，１１の上部軸端に螺着されてガイド穴２３に嵌装されている。
【００２３】
横軸２の操作部３の反対側の軸端に螺合する第１駒５の外側の端面に当接して横軸２をゆるめ方向に回転させたときの駒部材５ｂのエンドストップとなる止ねじ２１が設けられている。
横軸２に螺合する駒部材５ａ，５ｂは心押台１の下面に平行に穿孔された角孔又は丸穴に嵌装されており、加工上又は組立上の容易性から決定されるがいずれの穴形状でも良い。
【００２４】
次に本発明の作用について図１で説明する。
横軸２の操作部３を心押台１をベッド９に固定する方向に回転操作する。横軸２と螺合する駒部材５ａ，５ｂは横軸２に刻設された右ねじ，左ねじにより第１，第２駒を接近する方向に移動する。駒部材５ａ，５ｂのテーパ面に係合する駒部材６ａ，６ｂは駒部材５ａ，５ｂの移動に対応して嵌装されている穴の上方向へ移動する。
【００２５】
駒部材６ａ，６ｂと上部軸端で螺合して一体で上下に移動可能に設けられた縦軸７，１１も上方向に同時に移動する。縦軸７，１１を引きつづき上昇させて行くと、縦軸７，１１の移動方向の反対側軸端で螺合するナット１３の上端面で支持されている固定板８を持ち上げて、固定板８の上面とベッド９の下面が当接する状態となる。
【００２６】
横軸２に更に強い操作トルクを加えると固定板８の上面と心押台１の下面とでベッド９を挟持して心押台１は固定されることとなる。心押台をベッド９の摺動面上で移動可能にするには操作部３をゆるめ方向に回転させ横軸２と螺合する駒部材５ｂが止ねじ２１に当接するまで操作すれば良い。
本固定方法によれば１個所を操作することによりテーパ面を有する駒部材５ａ，５ｂ，６ａ，６ｂを利用して緊定力を増大させて２個所の固定板８に伝えて強固な固定にすることができる。
【００２７】
〔実施例２〕
図２，図３はベッド９上の傾斜摺動面上に心押台が載架された実施例である。横軸と縦軸及び係合する駒部材５ａ，５ｂ，６ａ，６ｂの構成と作用は実施例１と同様であり説明を省略する。
図２において、心押台１は傾斜摺動面２４上に載架されＸ軸方向へ案内のため心押台１の下部に設けた顎が摺動面２５に当接している。心押台に重力方向に縦軸７，１１を設け、実施例１と同様な移動手段の横軸２及び楔状部材である駒部材５ａ，５ｂ，６ａ，６ｂを配設する。
固定板８はベッド９の摺動面２６と平行になるように移動手段である縦軸７，１１と係合する穴は傾斜孔として加工され、ベッド９の摺動面２６，２７と当接している。
【００２８】
本実施例の作用について説明する。心押台１は移動時には当接面２４，２５に接して摺動し、固定時には縦軸７，１１で引上げられる固定板８の段差部分でベース９の２６，２７の面に当接して固定される。
本実施例ではベッド９の固定される面２４，２６と縦軸７，１１とは一定の角度を形成しているのでベッド９の当接面２５と２７で反対方向の作用力を生じさせることができるので心押台１の安定した固定が確保である。
【００２９】
〔実施例３〕
図３は図２と同じくベッド９の傾斜した摺動面上に心押台１が載架されている場合であるが、移動手段である横軸２と縦軸７，１１を係合する楔状部材である駒部材５ａ，５ｂ，６ａ，６ｂをいずれも丸穴に装備した例である。
心押台１はベッド９の傾斜した摺動面上に載架され、下部にＸ軸方向へ案内となる顎を設けているのは図２に示す実施例と同じである。
【００３０】
本実施例ではベッド９の傾斜した摺動面に直角に縦軸７，１１が設けられている。係合する駒部材５ａ，５ｂは丸穴に嵌装可能な形状に作られている。縦軸７，１１と下端で係合する固定板８の形状を本実施例では固定板１５と第３駒１４で構成している。
縦軸７，１１の引上げに対応して軸端のナット１３の上面に当接する第３駒１４を同時に引き上げる。
第３駒１４のテーパ面と、第３駒１４が嵌装され前記テーパ面と対を形成するテーパ面を有する固定板１５を引上げ、ベッド９の２６と当接する第３駒１４はベッドの２７と当接して案内されテーパ面の作用により固定板１５はベッドの２５に当接する。
【００３１】
本実施例における作用は、摺動面と縦軸が直交しているので心押台１の内部構成が直交座標系で与えられ加工上も実施が容易である。
また縦軸７，１１の引上げで第３駒１４を引上げると固定駒１４のテーパ面と固定板１５のテーパ面の作用により固定板１５がベース９の当接面２５と第３駒１４が２７で当接し反対方向の力を作用させて心押台１の固定が安定する。
【００３２】
〔実施例４〕
図４において、本実施例では楔状部材の楔状板３１は摺動面の裏面に当接して設けられ、移動手段の調整部材はねじ軸を有するジャッキボルトである。楔が心押台本体の進退方向に移動して摺動面と心押台固定部材との隙間をつめて心押台本体を摺動面上に固定するようにした実施例である。
【００３３】
図４（ａ）は楔状部材、ジャッキボルト及びクランプ部材のボルトを含む断面図、（ｂ）はクランプ部材を示す（ａ）のＡ−Ａ断面図、（ｃ）は裏板緊定具の部分を示す（ａ）のＢ−Ｂ断面図である。
【００３４】
図４（ａ）において、心押台１はベッド９の摺動面２４に橋設されワーク１０の長手形状に対応して心押軸３１のストローク範囲外の場合は心押台１をその都度長手方向に移動させる。更に心押台１は図示しない主軸の軸線方向に進退自在に対向する摺動面２５，２６にも案内されている。
【００３５】
本実施例ではベッド９の摺動面の裏面２６に当接する楔状に形成された楔状板３１が設けられ、該楔状板はベッド９の二つの摺動面２４ａ，２４ｂに橋設されたブロック３２とで摺動面２４，２６を挟持可能に設けられている。楔状板３１とブロック３２はクランプ部材のボルト３３，ナット３４により楔状板３１とブロック３２を貫通して設けた穴にボルト３３を通し、ベッド９の摺動面２４，２６を挟持する。本実施例において楔状部材は楔状板３１と裏板３５に相当する。
【００３６】
楔状板３１を下方から該楔状板を中にして心押台１と挟持可能に片面がテーパに形成されており、そのテーパ面上に突出し心押台下面１ａと当接する平面を形成した座部３５ａの中央部分にボルト３６を挿入可能な穴が設けられている。
裏板３５は、心押台１と緊定材のボルト３６，ナット３７により連結されベッド９の摺動面２４，２６を挟持しクランプする。
座部３５ａは、楔状板３１に設けられた穴３１ａを貫通し該楔状板が心押台の進退方向に移動自在に隙間が設けられている。ボルト３６の軸方向と楔状板３１の移動方向に直交する方向に対しては楔状板３１は座部３５ａの側面で案内されている。
【００３７】
又ブロック３２と心押台１とを接近離間させる移動手段であるジャッキボルト３８が設けられており、該ジャッキボルトの一端は回転のみ可能に支持され他端は螺切され該ジャッキボルトを回転させることによりブロック３２と心押台１が接近若しくは離間してブロック３２と連動する楔状板３１が心押台１の移動方向に移動自在である。
【００３８】
次に実施例４の心押台固定機構の作用について図４（ａ）（ｂ）（ｃ）に基づき説明する。
【００３９】
心押台１を摺動面２４に固定するに先立ち最初の調整が必要である。まずナット３４を締定方向に回しボルト３３によりクランプ用の楔状板３１を引き上げ、ブロック３２とで摺動面２４，２６を挟み摺動可能な範囲まで挟み込む。次にナット３７を締定方向に回しボルト３６により裏板３５を引き上げ、該裏板を心押台下面１ａに当接させ固定する。このとき楔状板３１が裏板３５に接しないようにブロック３２をジャッキボルト３８により心押台１に接近する方向に楔状板３１と共に移動させておく。この状態では心押台１と楔状板３１は一体で移動可能である。
【００４０】
先ず心押台１について、ワーク１０に対応して図示しない主軸軸心方向に心押台１を移動させて長手方向の位置を定める。ブロック３２をジャッキボルト３８により心押台１から離れる方向へ移動させると、楔状板３１の下面が裏板３５に接し、楔状板３１が摺動面２６と裏板３５の上面間の楔面で強固に相互に位置が固定された状態でクランプ部材のナット３４を締めてブロック３２をボルト３３で摺動面２４にクランプする。
【００４１】
これで心押台１のクランプは終了したことになり、後は心押軸３９を前進操作してワーク１０を取り付けることにより準備作業を完了する。ワーク１０を取り付けることによりその反力成分は楔状板３１で形成した楔効果を更に高める方向に作用し心押台１の位置は強固に維持されることとなる。
アンクランプの時はクランプ部材のナット３４を弛め、ジャッキボルト３８を操作して心押台１側へブロック３２を移動させることにより楔効果は消滅し心押台１は移動自在となる。このように心押台１の近傍に設けたブロック３２上のナット３４とジャッキボルト３８の操作のみでクランプ・アンクランプが可能であり操作性が特に良好である。
【００４２】
【発明の効果】
本発明の心押台固定機構は上述の通り構成されているので次に記載する効果を奏する。
【００４３】
請求項１記載の発明は、心押台を固定する操作を操作性の良い１個所で集中して行うことができ、また複数個所の固定板に、テーパ面で係合する駒部材を用いて作用力を増大させ伝えているので強固な固定力を得る効果を有する。
【００４４】
請求項２記載の発明は、固定に要する操作力をねじにより伝えているので固定操作に大きな力を要しない。従って複数の固定板に操作力を伝えることも可能となる効果を有する。
【００４５】
請求項３記載の発明は、心押台を傾斜摺動面上に固定する場合に、両者間の相互位置関係により生ずる分力を利用してＸ方向の位置決めと固定が容易となる効果がある。
【００４６】
請求項４記載の発明は、心押台を傾斜する摺動面に固定する場合でも、テーパ面を有する固定コマで有効固定分力を発生させて固定し、安定な固定状態が得られる効果を有するものである。
【００４８】
請求項５記載の発明は、楔面を有する固定部材の楔状板をねじ部材のジャッキボルトを操作して心押台の進退方向に移動させるのみで強固な楔結合を形成させ、その後ナット一個の操作のみで心押台を固定することができる構造であり、構成する部品数が少なく形状も剛性に富んでおり経済性良く固定用ナットとジャッキボルトのクランプ・アンクランプの操作が心押台の前側のみでできるので、カバーの取り外しを必要とせず操作性もすぐれた心押台の固定機構である。
【図面の簡単な説明】
【図１】本発明に係る心押台の固定機構の断面説明図（実施例１）である。
【図２】心押台が傾斜摺動面に固定される実施例２の断面図である。
【図３】心押台が傾斜摺動面に固定される実施例３の断面図である。
【図４】心押台を摺動面下面に当接する楔状板で固定する実施例４の図面である。（ａ）は楔状部材、ジャッキボルト及びクランプ部材を含む断面図、（ｂ）はクランプ部材を示す（ａ）のＡ−Ａ断面図、（Ｃ）は裏板緊定具を示す（ａ）のＢ−Ｂ断面図である。
【図５】従来技術による心押台の操作上の課題説明図である。
【図６】従来技術による心押台の、（ａ）は断面説明図、（ｂ）は傾斜摺動面固定の断面説明図である。
【符号の説明】
１心押台２横軸（操作用）
５第１駒６第２駒
５ａ，５ｂ駒部材６ａ，６ｂ駒部材
７，１１縦軸８，１５固定板
９ベッド１０ワーク
１４第３駒
２４，２５，２６，２７摺動面
３１楔状板３２ブロック
３３ボルト３４ナット
３５裏板３６ボルト
３７ナット３８ジャッキボルト
３９心押軸[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing mechanism for a tailstock used for a center work of a machine tool.
[0002]
[Prior art]
FIG. 5 which shows a prior art shows the example of arrangement | positioning of the tailstock in a lathe. The tailstock 101 is provided so as to be movable concentrically with the chuck 104 on the sliding surface 103 of the bed 102. After the tailstock 101 is moved according to the length of the workpiece 105, the tailstock 101 is fixed to the sliding surface 103. At this time, a bolt 106 is tightened with a spanner and a clamp lever (not shown) and an eccentric shaft are provided at a position where the bolt 106 is located beyond the tailstock 101 and does not obstruct the operator's operation of the machine base, and clamped on the sliding surface 103. There is a way.
[0003]
6 (a) and 6 (b) show another conventional example of the fixing mechanism.
This is a case where the tailstock 101 is placed on the inclined sliding surface 111. When the fixing bolt 106 is directly rotated in the fixing direction by a spanner, the fixing plate 112 engaged with the lower portion of the bolt 6 is lifted, and the sliding surface 111 is sandwiched between the lower surface of the tailstock 101 and the fixing plate 112 and the tailstock is pushed. The base 101 is fixed. Since the nut 113 is screwed onto the bolt 106 and is then prevented from loosening by the pin 114, the fixing plate 112 will not fall.
[0004]
Further, an operation of making the engaging portion of the bolt 106 with the fixing plate 112 a swing fulcrum, providing a through hole in the head of the bolt 106 at a right angle to the axis of the bolt, and making the portion fitted into the through hole an eccentric cylindrical shape. A horizontal axis may be provided.
[0005]
[Problems to be solved by the invention]
In the lathe shown in FIG. 5, a spanner or a clamp lever is often operated manually. Most machine components are covered with a cover for the purpose of pursuing high productivity of the machine and safety and working environment problems. Therefore, before performing the tailstock 101 clamping operation, it is necessary to open and operate the front window 107 or the side window 108. If the fixing bolts 106 are provided at two or more places, it takes time.
[0006]
Further, since the fixing and loosening operations are repeated, a tightening reaction force is directly applied to the threaded portion of the bolt 106, and the threaded portion is worn out over a long period of use, thereby reducing the stability of the fixing. When the tailstock 101 is increased in size, a large fixing force is required, but it is difficult to obtain a sufficient fixing force when the bolt 106 is directly operated by hand tightening work.
[0007]
In the case of the tailstock 101 mounted on the inclined sliding surface 111 shown in FIGS. 6A and 6B, the sliding surface is the Y surface 116 and the X surface 117 of the guide surface in the X-axis direction is The raised portion 115 of the tailstock 101 abuts and the tailstock 101 is guided. In this case, when the tailstock 101 is fixed with the bolt 106, the tailstock 101 is not always fixed in a state of being in contact with the X plane, so that the position in the X-axis direction cannot be determined.
[0008]
The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to use a tailstock mounted on a flat surface or an inclined surface with a small tightening force and a large tightening force with high accuracy. It is intended to provide a mechanism that can be fixed to the sliding surface.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention of the tailstock fixing mechanism according to claim 1 is a mechanism for fixing the tailstock to the sliding surface, and abuts the back surface of the sliding surface to fix the tailstock. A fixed plate, a plurality of vertical axes that have engaging portions with the fixed plate at an axial end so that the fixed plate can be pulled up, and a plurality of vertical axes that are arranged in parallel to each other; A horizontal axis having a threaded portion, a first piece fixed to the upper shaft end of each of the plurality of vertical axes and having a tapered surface on the lower surface, and a threaded surface threaded on the threaded portion on the horizontal axis, respectively. The tail piece is fixed by pulling up the vertical axis by rotating the horizontal axis. is there.
[0010]
According to the first aspect of the present invention, since the tightening force of the rotational operation force applied to the horizontal axis is expanded by at least the taper engaging portion of the piece, it is possible to firmly fix the tailstock. Since less force is applied to the screw threaded on the horizontal axis, there is less wear on the screw, and stable fixation can be expected over a long period of time.
[0011]
Further, in the invention of the tailstock fixing mechanism according to a second aspect, the threaded portion of the horizontal axis is provided at two locations and is formed in screws in opposite directions.
Since the pieces 5a and 5b engaged with the horizontal axis and the horizontal axis by screws are formed by screws opposite to each other, the tailstock is moved at a plurality of locations by a light operation at one end of the horizontal axis. It can be firmly fixed.
[0012]
Further, the invention of the tailstock fixing mechanism according to claim 3 is a mechanism for fixing the tailstock to the sliding surface, wherein the vertical axis pulls up the fixing plate that holds the sliding surface with the bottom surface of the tailstock. A first piece that engages and has a tapered surface on the lower surface and a second piece that engages with the tapered surface on the upper surface and increases the clamping force by relative movement are provided, and the second piece is parallel to the sliding surface. Moving means for moving in any direction, the vertical axis is inclined with respect to the sliding surface and is movable up and down in the inclined direction, and the angle of the sliding surface when the vertical axis is pulled up by the fixed plate A stepped portion that abuts against the end surface of the portion, and moves the second piece by the moving means to lift at least one of the corners facing the sliding surface when the fixed plate is pulled up through the vertical axis . The corner portion is fixed by applying a component of the lifting force.
[0013]
In order to stably fix the tailstock on the inclined sliding surface on the sliding surface of the base, not only the upper and lower surfaces of the inclined sliding surface are sandwiched from above and below, but also the vertical axis is inclined. By utilizing the component force at the time of pulling generated due to the relationship with the sliding surface, the position of the tailstock in the X direction can be stabilized at the corners of the opposing sliding surface.
[0014]
Further, the invention of the tailstock fixing mechanism according to claim 4 is a mechanism for fixing the tailstock to the sliding surface, and relates to the vertical axis for pulling up the fixing plate that holds the sliding surface with the bottom surface of the tailstock. A first piece having a tapered surface on the lower surface and a second piece that engages with the tapered surface on the upper surface and increases the clamping force by relative movement, and the second piece is parallel to the sliding surface. A moving step for moving in the direction, a step that contacts the sliding surface on one side of the fixed plate, and a step that contacts the sliding surface on the other side, forming a contact stepped portion and a notch portion having a taper surface at the deepest portion. A third piece that is formed in the notch and is in contact with the innermost end surface of the sliding surface that is fitted into the notch and is in contact with the innermost end surface of the sliding surface ; and the lower surface of the sliding surface of the component force generated by the tapered surface of the third piece when pulled up the vertical axis by moving the frame It is obtained so as to fix the tailstock tell plane.
[0015]
In order to stably fix the tailstock on the inclined sliding surface on the sliding surface of the base, the third surface provided on the fixing plate not only clamps the upper and lower surfaces of the inclined sliding surface from the vertical direction. It is designed to support the X direction component force of the tailstock using the action of the tapered surface of the piece, and stable fixation can be expected from this structure.
[0017]
Further, the invention of the tailstock fixing mechanism according to claim 5 is a mechanism for fixing the tailstock to the sliding surface, a wedge-shaped wedge-shaped plate contacting the back surface of the sliding surface, and the tailstock A block mounted on the sliding surface in the vicinity and provided integrally with the wedge-shaped plate so as to be movable in the advancing and retreating direction of the tailstock, and a clamp member for fixing the block and the wedge-shaped plate to the sliding surface; A back plate that is in contact with the tapered surface of the lower surface of the wedge-shaped plate and is integrally fixed to the lower surface of the tailstock placed on the sliding surface; and an adjustment member that moves the block and the tailstock closer to and away from each other. The adjusting member is operated so that the wedge-shaped plate is moved in the advancing and retreating direction of the tailstock, the wedge effect is operated, and the rear clamp member is fixed.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory sectional view of a fixing mechanism for a tailstock according to the present invention (Embodiment 1), and FIGS. 2 and 3 are sectional views when the tailstock is fixed to an inclined sliding surface (Example 2). , Embodiment 3) and FIG. 4 are sectional views (Example 4) of a wedge-shaped member, a jack bolt, and a clamp member that fix the tailstock with a wedge-shaped plate that abuts the lower surface of the sliding surface.
[0019]
[Example 1]
FIG. 1 shows an embodiment of a tailstock fixing structure provided on a tailstock 1 mounted on a horizontal sliding surface on a bed 9. When operating the operating portion 3 at the shaft end of the horizontal shaft 2 that is a moving means, or by attaching an operation lever (not shown) to the shaft end, the tailstock 1 can be fixed with good workability.
[0020]
In FIG. 1, the tailstock 1 is placed on a bed 9 having a horizontal sliding surface. When the vertical axes 7 and 11 are lowered, the fixed plate 8 is also lowered and the state where the bed 9 is held is removed. The tailstock 1 is provided so as to be manually movable in the Z-axis direction. During center work, the tailstock must be moved and fixed frequently in order to adjust the distance between the headstock chuck and the tailstock shaft according to the length of the workpiece in the axial direction.
In particular, when the tailstock is a large machine or the tailstock 1 is on an inclined sliding surface, it is necessary to form a structure in which the tailstock is firmly fixed to the bed 9 manually.
[0021]
The structure of the tailstock fixing mechanism of the present invention will be described with reference to FIG. The tailstock 1 is engaged with a nut 13 which is screwed into the lower end of the vertical axis by the ascent of the vertical axes 7 and 11 and is prevented from being loosened by the non-rotating pin 12. It fixes to the sliding surface of the bed 9 with the fixing plate 8 to engage. In order to cause the vertical axis 7 and 11 to move in the vertical direction, piece members 5a, 5b, 6a, and 6b, which are wedge-shaped members engaged with the taper surface between the horizontal axis 2 orthogonal to the vertical axes 7 and 11, are provided. The rotation of the horizontal axis 2 is converted into the vertical movement of both vertical axes 7 and 11 by the relative displacement of the piece members 5a, 5b, 6a and 6b.
[0022]
It has an operating portion 3 at the shaft end of the shaft which is projected outside the tailstock and can be rotated by hand and is provided in parallel with the sliding surface of the bed 9 in the two directions from the shaft center to the shaft end. A horizontal shaft 2 engraved with a right screw and a left screw, and a piece member 5a, 5b having a penetrating right screw or left screw and having a tapered surface on the upper surface is fitted in the guide hole 22 and is a threaded portion of the horizontal shaft 2 And the taper members 6a and 6b having tapered surfaces that abut against the upper surfaces of the taper surfaces of the piece members 5a and 5b are formed on the first and second longitudinal axes 7 and 11, respectively. It is screwed into the upper shaft end and fitted into the guide hole 23.
[0023]
A stop that is an end stop of the piece member 5b when the horizontal shaft 2 is rotated in the loosening direction by contacting the outer end surface of the first piece 5 screwed to the shaft end of the horizontal shaft 2 opposite to the operation portion 3. A screw 21 is provided.
The piece members 5a and 5b screwed to the horizontal shaft 2 are fitted in square holes or round holes drilled in parallel to the lower surface of the tailstock 1, and are determined from the viewpoint of ease of processing or assembly. Any hole shape may be used.
[0024]
Next, the operation of the present invention will be described with reference to FIG.
The operation unit 3 of the horizontal axis 2 is rotated in a direction to fix the tailstock 1 to the bed 9. The piece members 5a and 5b screwed to the horizontal shaft 2 are moved in the direction in which the first and second pieces are approached by the right and left screws engraved on the horizontal shaft 2. The piece members 6a and 6b engaged with the tapered surfaces of the piece members 5a and 5b move upward in the holes fitted in response to the movement of the piece members 5a and 5b.
[0025]
The vertical axes 7 and 11 provided so as to be integrally movable by screwing at the top shaft ends with the piece members 6a and 6b are also simultaneously moved in the upward direction. When the vertical axes 7 and 11 are continuously raised, the fixing plate 8 supported by the upper end surface of the nut 13 screwed at the shaft end opposite to the moving direction of the vertical axes 7 and 11 is lifted to fix the fixing plate. The upper surface of 8 and the lower surface of the bed 9 come into contact with each other.
[0026]
When a stronger operating torque is applied to the horizontal shaft 2, the tailstock 1 is fixed by sandwiching the bed 9 between the upper surface of the fixing plate 8 and the lower surface of the tailstock 1. In order to make the tailstock moveable on the sliding surface of the bed 9, the operation unit 3 is rotated in the loosening direction and operated until the piece member 5 b screwed with the horizontal shaft 2 contacts the set screw 21.
According to this fixing method, the tightening force is increased using the piece members 5a, 5b, 6a, and 6b having tapered surfaces by operating one place, and transmitted to the two fixing plates 8 for strong fixing. can do.
[0027]
[Example 2]
2 and 3 show an embodiment in which a tailstock is mounted on an inclined sliding surface on the bed 9. The configuration and operation of the horizontal and vertical axes and the engaging piece members 5a, 5b, 6a, and 6b are the same as those in the first embodiment, and a description thereof will be omitted.
In FIG. 2, the tailstock 1 is mounted on the inclined sliding surface 24, and a jaw provided at the lower portion of the tailstock 1 for guiding in the X-axis direction is in contact with the sliding surface 25. The tailstock is provided with the vertical axes 7 and 11 in the direction of gravity, and the horizontal axis 2 of the moving means similar to that of the first embodiment and the piece members 5a, 5b, 6a and 6b which are wedge-shaped members are disposed.
The fixed plate 8 is processed as an inclined hole so that it is in contact with the sliding surfaces 26 and 27 of the bed 9 so that the holes engaging with the longitudinal axes 7 and 11 as moving means are parallel to the sliding surface 26 of the bed 9. ing.
[0028]
The operation of the present embodiment will be described. The tailstock 1 slides in contact with the contact surfaces 24 and 25 when moving, and is fixed by contacting the surfaces 26 and 27 of the base 9 at the stepped portion of the fixing plate 8 lifted by the vertical axes 7 and 11 when fixed. Is done.
In the present embodiment, the surfaces 24 and 26 to which the bed 9 is fixed and the vertical axes 7 and 11 form a fixed angle, so that the abutting surfaces 25 and 27 of the bed 9 generate acting forces in opposite directions. Therefore, stable fixation of the tailstock 1 is ensured.
[0029]
Example 3
FIG. 3 shows a case in which the tailstock 1 is mounted on the inclined sliding surface of the bed 9 as in FIG. 2, but a wedge shape that engages the horizontal axis 2 and the vertical axes 7 and 11 as moving means. In this example, the piece members 5a, 5b, 6a, and 6b, which are members, are all mounted in a round hole.
The tailstock 1 is mounted on an inclined sliding surface of the bed 9 and has a chin that serves as a guide in the X-axis direction in the lower part as in the embodiment shown in FIG.
[0030]
In this embodiment, the vertical axes 7 and 11 are provided at right angles to the inclined sliding surface of the bed 9. The engaging piece members 5a and 5b are formed in a shape that can be fitted into a round hole. In this embodiment, the shape of the fixing plate 8 engaged with the vertical axes 7 and 11 at the lower end is constituted by the fixing plate 15 and the third piece 14.
The third piece 14 that contacts the upper surface of the nut 13 at the shaft end is simultaneously pulled up corresponding to the pulling up of the vertical axes 7 and 11.
The fixing plate 15 having the tapered surface of the third piece 14 and the tapered surface into which the third piece 14 is fitted and which forms a pair with the tapered surface is pulled up, and the third piece 14 contacting the 26 of the bed 9 is the 27 of the bed. The fixed plate 15 comes into contact with the bed 25 by the action of the tapered surface.
[0031]
Since the sliding surface and the vertical axis are orthogonal to each other in the present embodiment, the internal structure of the tailstock 1 is given by an orthogonal coordinate system and is easy to implement.
When the third piece 14 is pulled up by the vertical axes 7 and 11, the fixed plate 15 is brought into contact with the contact surface 25 of the base 9 and the third piece 14 by the action of the tapered surface of the fixed piece 14 and the tapered surface of the fixed plate 15. The tailstock 1 is stably fixed by abutting at 27 and applying a force in the opposite direction.
[0032]
Example 4
4, in this embodiment, the wedge-shaped plate 31 of the wedge-shaped member is provided in contact with the back surface of the sliding surface, and the adjusting member of the moving means is a jack bolt having a screw shaft. In this embodiment, the wedge is moved in the advancing and retreating direction of the tailstock main body, and the gap between the sliding surface and the tailstock fixing member is filled to fix the tailstock main body on the sliding surface.
[0033]
4A is a cross-sectional view including a wedge-shaped member, a jack bolt, and a bolt of a clamp member, FIG. 4B is a cross-sectional view of the clamp member taken along the line AA in FIG. 4C, and FIG. It is BB sectional drawing of (a) which shows this.
[0034]
In FIG. 4A, the tailstock 1 is bridged on the sliding surface 24 of the bed 9 and corresponds to the longitudinal shape of the workpiece 10 and is outside the stroke range of the tailstock shaft 31. Move in the longitudinal direction. Further, the tailstock 1 is also guided by sliding surfaces 25 and 26 facing each other so as to freely advance and retreat in the axial direction of the main shaft (not shown).
[0035]
In this embodiment, a wedge-shaped plate 31 formed in a wedge shape that abuts against the back surface 26 of the sliding surface of the bed 9 is provided, and the wedge-shaped plate is a block 32 bridged by the two sliding surfaces 24 a and 24 b of the bed 9. The sliding surfaces 24 and 26 are provided so as to be clamped. The wedge-shaped plate 31 and the block 32 pass the bolt 33 through holes provided through the wedge-shaped plate 31 and the block 32 by bolts 33 and nuts 34 of clamp members, and sandwich the sliding surfaces 24 and 26 of the bed 9. In this embodiment, the wedge-shaped member corresponds to the wedge-shaped plate 31 and the back plate 35.
[0036]
One side is tapered so that the wedge-shaped plate 31 can be sandwiched with the tailstock 1 with the wedge-shaped plate inside from below, and a seat that forms a flat surface that protrudes on the tapered surface and contacts the tailstock lower surface 1a. A hole into which the bolt 36 can be inserted is provided in the central portion of 35a.
The back plate 35 is connected to the tailstock 1 by bolts 36 and nuts 37 of tightening materials, and clamps and clamps the sliding surfaces 24 and 26 of the bed 9.
The seat portion 35a passes through a hole 31a provided in the wedge-shaped plate 31, and a gap is provided so that the wedge-shaped plate can move in the advancing and retracting direction of the tailstock. The wedge-shaped plate 31 is guided by the side surface of the seat portion 35a with respect to the direction orthogonal to the axial direction of the bolt 36 and the moving direction of the wedge-shaped plate 31.
[0037]
A jack bolt 38 as a moving means for moving the block 32 and the tailstock 1 closer to and away from each other is provided. One end of the jack bolt is supported to be rotatable only, and the other end is threaded to rotate the jack bolt. As a result, the block 32 and the tailstock 1 approach or separate from each other, and the wedge-shaped plate 31 interlocked with the block 32 is movable in the movement direction of the tailstock 1.
[0038]
Next, the operation of the tailstock fixing mechanism according to the fourth embodiment will be described with reference to FIGS. 4 (a), 4 (b), and 4 (c).
[0039]
Prior to fixing the tailstock 1 to the sliding surface 24, an initial adjustment is required. First, the nut 34 is turned in the tightening direction, and the wedge-shaped plate 31 for clamping is pulled up by the bolt 33, and the sliding surfaces 24 and 26 are sandwiched between the blocks 32 to the extent that they can slide. Next, the nut 37 is turned in the tightening direction, the back plate 35 is pulled up by the bolt 36, and the back plate is brought into contact with and fixed to the tailstock lower surface 1a. At this time, the block 32 is moved together with the wedge-shaped plate 31 in the direction approaching the tailstock 1 by the jack bolt 38 so that the wedge-shaped plate 31 does not contact the back plate 35. In this state, the tailstock 1 and the wedge-shaped plate 31 can move together.
[0040]
First, with respect to the tailstock 1, the tailstock 1 is moved in the direction of the spindle axis (not shown) corresponding to the workpiece 10 to determine the position in the longitudinal direction. When the block 32 is moved away from the tailstock 1 by the jack bolt 38, the lower surface of the wedge-shaped plate 31 contacts the back plate 35, and the wedge-shaped plate 31 is the wedge surface between the sliding surface 26 and the upper surface of the back plate 35. In a state where the positions are firmly fixed to each other, the nut 34 of the clamp member is tightened and the block 32 is clamped to the sliding surface 24 with the bolt 33.
[0041]
The clamping of the tailstock 1 is now complete, and thereafter the preparatory work is completed by operating the tailstock 39 forward and attaching the workpiece 10. By attaching the workpiece 10, the reaction force component acts in a direction to further enhance the wedge effect formed by the wedge-shaped plate 31, and the position of the tailstock 1 is firmly maintained.
When unclamping, the nut 34 of the clamp member is loosened and the jack bolt 38 is operated to move the block 32 to the tailstock 1 side, so that the wedge effect disappears and the tailstock 1 becomes movable. Thus, clamping and unclamping can be performed only by operating the nut 34 and the jack bolt 38 on the block 32 provided in the vicinity of the tailstock 1, and the operability is particularly good.
[0042]
【The invention's effect】
Since the tailstock fixing mechanism of the present invention is configured as described above, the following effects can be obtained.
[0043]
According to the first aspect of the present invention, the operation of fixing the tailstock can be performed in a centralized manner with good operability, and a piece member engaged with a tapered surface on a plurality of fixing plates is used. Since the acting force is increased and transmitted, it has an effect of obtaining a strong fixing force.
[0044]
According to a second aspect of the invention does not require a large force to the fixed operation since the operating force required for fixing is conveyed by a screw. Therefore, it is possible to transmit the operating force to a plurality of fixing plates.
[0045]
According to the third aspect of the present invention, when the tailstock is fixed on the inclined sliding surface, there is an effect that positioning and fixing in the X direction are facilitated by using the component force generated by the mutual positional relationship between the two. .
[0046]
According to the fourth aspect of the present invention, even when the tailstock is fixed to the inclined sliding surface, an effective fixing component force is generated and fixed by a fixing piece having a tapered surface, and a stable fixing state can be obtained. It is what you have.
[0048]
According to the fifth aspect of the present invention, the wedge-shaped plate of the fixing member having the wedge surface is moved by moving the jack bolt of the screw member in the advancing / retreating direction of the tailstock, and then a strong wedge connection is formed. The structure allows the tailstock to be fixed only by operation, and the number of components is small and the shape is rigid.The nut and jack bolt clamp and unclamp operations are economically efficient. Since it can be done only on the front side, it is a tailstock fixing mechanism that does not require removal of the cover and has excellent operability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional explanatory view (Example 1) of a fixing mechanism for a tailstock according to the present invention.
FIG. 2 is a cross-sectional view of a second embodiment in which the tailstock is fixed to the inclined sliding surface.
FIG. 3 is a cross-sectional view of a third embodiment in which the tailstock is fixed to the inclined sliding surface.
FIG. 4 is a drawing of a fourth embodiment in which the tailstock is fixed with a wedge-shaped plate that is in contact with the lower surface of the sliding surface. (A) is a cross-sectional view including a wedge-shaped member, a jack bolt, and a clamp member, (b) is a cross-sectional view taken along the line AA of (a) showing the clamp member, and (C) is a back plate fastener. It is BB sectional drawing.
FIG. 5 is a diagram for explaining a problem in operation of a tailstock according to the prior art.
6A is a cross-sectional explanatory view of a tailstock according to the prior art, and FIG. 6B is a cross-sectional explanatory view of fixing an inclined sliding surface.
[Explanation of symbols]
1 Tailstock 2 Horizontal axis (for operation)
5 First piece 6 Second piece 5a, 5b Piece member 6a, 6b Piece member 7, 11 Vertical axis 8, 15 Fixed plate 9 Bed 10 Work 14 Third piece 24, 25, 26, 27 Sliding surface 31 Wedge plate 32 Block 33 Bolt 34 Nut 35 Back plate 36 Bolt 37 Nut 38 Jack bolt 39 Tailstock

Claims

A mechanism for fixing the tailstock to the sliding surface, the fixing plate being in contact with the back surface of the sliding surface to fix the tailstock and the fixing plate being connected to the fixing plate at the shaft end so that the fixing plate can be pulled up. A plurality of longitudinal axes arranged in parallel with each other, a horizontal axis provided in a direction perpendicular to the plurality of longitudinal axes and having a plurality of screw portions, and an upper shaft end of each of the plurality of longitudinal axes A first piece fixed to the bottom surface and having a tapered surface on the lower surface, and a second piece engaged with the first piece, each having a tapered surface on the upper surface and screwed into the threaded portion of the horizontal axis. A tailstock fixing mechanism comprising a frame and fixing the tailstock by pulling up the vertical axis by rotating the horizontal axis .

The tailstock fixing mechanism according to claim 1, wherein the threaded portion of the horizontal axis is provided at two locations and is formed as a screw in a direction opposite to each other.

A mechanism for fixing a tailstock to a sliding surface, a first piece having a tapered surface on the lower surface and an upper surface engaged with a vertical axis that pulls up a fixing plate that sandwiches the sliding surface with the lower surface of the tailstock Provided with a second piece that engages with the tapered surface and increases the clamping force by relative movement, a moving means for moving the second piece in a direction parallel to the sliding surface, is inclined relative to the sliding surface and a vertically movable in the inclined direction, the vertical axis is provided in contact with the stepped portion on the end face of the corner portion of the sliding surface when the raised to the fixed plate, wherein The second piece is moved by a moving means, and fixed by applying a component of the pulling force to at least one of the corners facing the sliding surface when the fixed plate is pulled up via the vertical axis. Tailstock fixing mechanism.

A mechanism for fixing the tailstock to the sliding surface, the first plate having a taper surface on the lower surface and a first piece that engages with the vertical axis that pulls up the fixing plate that holds the sliding surface with the lower surface of the tailstock. A second piece that engages with the tapered surface and increases the clamping force by relative movement is provided, and a moving means that moves the second piece in a direction parallel to the sliding surface is provided, and slides on the fixed plate. A contact stepped portion is formed on one side contacting the surface and a notch portion having a taper surface at the deepest portion, and a stepped portion contacting the sliding surface is formed on the other side, and the cutout portion is fitted into the notch portion. A third piece that contacts the innermost end surface of the sliding surface and abuts against the taper surface of the deepest portion of the sliding portion, and moves the second piece by the moving means to pull up the vertical axis. The component force generated on the tapered surface of the three pieces is transmitted to the lower surface and the side surface of the sliding surface to fix the tailstock. That tailstock fixing mechanism.

A mechanism for fixing the tailstock to the sliding surface, and wedge-shaped plate abutting wedge-shaped on the rear surface of the sliding surface, the wedge-shaped plate integrally mounted on the sliding surface on the tailstock vicinity A block provided movably in the advancing and retreating direction of the tailstock, a clamp member for fixing the block and the wedge-shaped plate to the sliding surface, and a sliding surface in contact with the tapered surface of the lower surface of the wedge-shaped plate A back plate integrally fixed to the lower surface of the tailstock placed on the surface, and an adjustment member for moving the block and the tailstock close to and away from each other, and operating the adjustment member to center the wedge-shaped plate A tailstock fixing mechanism, wherein the tailstock is fixed by a rear clamp member by operating the wedge effect by moving it in the advancing and retreating direction of the tailstock.