JP4088072B2

JP4088072B2 - Retainer

Info

Publication number: JP4088072B2
Application number: JP2002004584A
Authority: JP
Inventors: 均石川
Original assignee: NT Tool Corp
Current assignee: NT Tool Corp
Priority date: 2002-01-11
Filing date: 2002-01-11
Publication date: 2008-05-21
Anticipated expiration: 2022-01-11
Also published as: JP2003205408A

Description

【０００１】
【発明の属する技術分野】
本発明は、工作機械において用いられている周知のドリル等の刃具又は加工を施すべき被工作物を保持するようにした保持具に関する。
【０００２】
【従来の技術】
従来より広く知られている保持具としては、図５に示されるものがある（例えば特開平６−２８５７０６号、特公平７−６７６４１号公報参照）。図５において、１は本体、２はその元部に備わった連結部で、工作機のスピンドルに取付けるようにした部分である。2aは本体１の先端部に備わった保持部を示す。該保持部2aにおいて、３は本体１と一体形成の締着筒で、半径方向に弾性変形可能に構成してあり、内部は被保持物を挿入する為の差込孔４となっている。５は締着筒３の内周面の締着面を示す。７は締着筒３の外周面を示し、連結部２の側が太くなるテーパ状に形成してある。次に締着筒３の周囲に配設した17は回動筒で、その内周面18は前記外周面７と平行なテーパ状に形成してある。又外周面には周知のスパナ掛溝19が形成してある。次に21は締着筒３と回動筒17の間に配設された筒状の案内筒で、周知の如く複数の案内孔22が周方向に形成されて鳥篭状（図３（Ｂ）参照）となっており、各案内孔22には１又は複数のローラ24が夫々回動自在に存置させてある。それらのローラ24は周知の如く案内筒21の中心軸線（締着筒３の中心軸線に一致）に対し、一定の角度を持ったねじれの位置の関係に置かれている。又これらのローラ24は周知のように締着筒３の周方向に複数のローラ群24aに分けられている（図３（Ｂ）参照）。25と、26は締着筒３の先端3aに周設した防塵用のゴムシールと、シール押え用のリングを示し、27は締着筒３の先端外周に止着し、案内筒21の抜脱を防止するようにした抜止用のサークリップを示す。25’と、26’は回動筒17の後端内周に止着し、案内筒21の抜脱を防止するようにした防塵用のゴムシールと、抜止用のサークリップを示す。
【０００３】
次に上記構成の保持具を用いて被保持物31例えば刃具（被工作物でもよい）を保持する操作について説明する。図５（Ａ）に示される前進状態の回動筒17の軸心位置に存在する差込孔４の内部に刃具31の元部を差し込む。次に回動筒17を時計回り方向に回動させる。すると上記多数のローラ24は案内筒21に案内されて上記の如きねじれの位置の関係となった状態で回転する。この為、上記回動筒17を回動させることにより、多数のローラ24は夫々締着筒３の外周の転動面７と回動筒17の内周の転動面18との間で転がりながら、外周面７に沿って螺旋状に締着筒３における太径部８の側に向けて後退する。これにより回動筒17も同方向に後退する。このように回動筒17が太径部８の側に向けて図５（Ｂ）の状態にまで後退すると、締着筒３は回動筒17によりローラ24を介して押し縮められることとなり、締着筒３は減径する。その結果締着面５は刃具の外周面に圧接し、これを強く締付ける。
上記のように被保持物31を締着して保持した状態においては、本体１を回転させることによって締着筒３及び被保持物31を回転させ、被保持物によって周知の如く機械加工（例ば切削）を行なう。
【０００４】
【発明が解決しようとする課題】
この従来の保持具では、締着筒３に対し回動筒17を回すことによって上記複数のローラーを転動させて、上記ローラーを保持する為のローラー案内筒21と、上記回動筒17とを軸線方向へ進退移動させて上記締着筒３を増減径させることができ、それにより内周面にて刃具を締着け緩め自在にして機械加工に提供することのできる利点がある。
【０００５】
しかしながら、締付筒３の先端にはローラー案内筒21の突出を防止する為の抜止用サークリップ27が装着されているので、締付筒３の締着けを緩めて刃具を抜き出す場合にローラー案内筒21と回動筒17の前進端位置は制限を受ける。このようにローラー案内筒21と回動筒17の前進端位置が制限を受けると、必然ローラ24の最先端の位置も図５（Ａ）から明らかなように締付筒３の最先端位置3aより後方に位置することになる。
【０００６】
そうすると、回動筒17とローラー案内筒21とを後退させた刃具締め付け装着状態においては図５（Ｂ）から明らかなように、最先端の位置にあるローラ24の位置は締付筒３の最先端位置3aよりかなり後方に後退した位置（寸法Ｌだけ後退した位置）になる。
刃具31をこのような締め付け状態において締め付けた場合には、締付筒３の最先端位置3aから寸法Ｌだけ後退した区間にあっては、十分な締め付け力を発揮させ難い問題点がある。
【０００７】
さらに図５（Ｂ）に示されるようにローラー案内筒21の突出防止用の付属物が締付筒３の先端に存在していたり、回動筒17の先端に配設してある状態で本体１を高速回転させると、ローラー案内筒21の突出防止用の付属物例えばサークリップ27が遠心力により脱出飛散し、作業員に対し不測の危害を加える問題点が発生する。
【０００８】
上記問題点を解決する為に、締付筒３の最先端位置3aにキャップを装着し、これを上記最先端位置3aにねじ止めする手段が講じられているものもある（例えば特開平11-77412号公報参照）。しかしこのように構成すると上記のキャップが締付筒３の最先端の縮小作用に抵抗を与える問題点が発生する。
さらに回動筒17の先端17aにローラー案内筒21の突出防止用の付属物を装着することも考えられるが、そのような付属物を装着すると締付筒３の先端3aからその付属物が大きく突出し、鍔が付された刃具の装着に支障をもたらす問題点が発生する。
【０００９】
本件出願の目的は、締着筒に対し回動筒を回すことによって複数のローラーを転動させて、ローラーを保持する為のローラー案内筒と、回動筒とを軸線方向へ進退移動させて締着筒を増減径させ、それにより内周面にて刃具を締着け緩め自在にして機械加工に提供することのできるようにした保持具を提供しようとするものである。
他の目的は、回動筒とローラー案内筒とを前進させた刃具装着準備状態（図２（Ａ）参照）において、ローラー案内筒の先端を締着筒の先端より前方に突出させ得るようにした保持具を提供しようとするものである。
他の目的は、回動筒とローラー案内筒とを後退させた刃具締付状態（図１参照）において、ローラー案内筒においてガイドされている複数のローラーの内、最先端のローラー位置が締着筒の先端に近い位置に止まり、締着筒の先端における締付力が大きくなるようにした保持具を提供しようとするものである。
他の目的は、上記のようにローラー案内筒の先端を締着筒の先端より前方に突出させ得るようにしたものであっても、回動筒やローラー案内筒が脱出することのないようにした保持具を提供しようとするものである。
他の目的は、一対の係止機構をローラー案内筒の後方に具備させることにより、これが高速回転中において飛散することのないように構成すると共に、そのように安全に構成したものであっても、ローラー案内筒の先端が前進位置において締着筒先端よりも突出しても抜脱しないようにした保持具を提供しようとするものである。
他の目的は、一対の係止機構をローラー案内筒の後方の内側に具備させることによりローラー案内筒の抜け止めができ、これにより締付筒の先端にも、回動筒の先端にもローラー案内筒21の突出防止用の付属物を省略することができ、さらに回動筒の抜け止めをも出来るようにした保持具を提供しようとするものである。
他の目的及び利点は図面及びそれに関連した以下の説明により容易に明らかになるであろう。
【００１０】
【課題を解決するための手段】
本願発明における保持具は、内側には前端側が開口した被保持物の差込孔が形成され、外周面にはローラーの転動面が形成され、半径方向には弾性変形可能にしてある筒状の締着筒と、
上記締着筒の周囲に相対回動可能に配設された回動筒と、
締着筒の外周面と回動筒の内周面との間に配設された複数のローラーとそれらのローラーを保持する為のローラー案内筒とを備え、
締着筒に対し回動筒を回すことによって上記複数のローラーを転動させて、上記ローラーを保持する為のローラー案内筒と上記回動筒とを軸線方向へ進退移動させて上記締着筒を増減径させ、その内周面により被保持物を締着け緩め自在にするようにしてある保持具において、
上記締着筒の後部側における外周面には、周方向に係合溝を周設し、
一方、上記締着筒の後部側外周面に設けられた上記係合溝に対向するローラー案内筒の後部側の内周面には、上記締着筒の後部側外周面に設けられた係合溝内に達するに充分な長さを備える係合子を備えさせ、
上記締着筒の後部側外周面に周設された係合溝の上記軸線方向の幅寸法は、ローラー案内筒が通常の進退移動範囲内で進退動することを係合子が妨げることなく、ローラー案内筒が前進端に至った場合には、上記係合子が溝端に接してローラー案内筒が上記前進端の位置から、前進動するのを阻止出来るような幅に設定し、
上記締着筒に対し回動筒を回すことによって上記複数のローラーを転動させて、上記ローラーを保持する為のローラー案内筒と上記回動筒とを軸線方向へ進退移動させるときには、上記係合子が上記締着筒の後部側外周面に設けられた上記係合溝を周方向に移動しながら、かつ、上記締着筒の軸線方向にも上記係合溝を、軸線方向の幅寸法の範囲内で進退移動するようにしたものである。
【００１１】
【発明の実施の形態】
以下本願発明の実施の形態を示す図面について説明する。図１乃至図４の説明に当り、前述の図５と同符号を用いた構成、部材等の機能、性質、特徴等は、以下に於て加える新規な部材構成、組合せ等の説明に係わる事項を除き、前述した説明と同旨と理解できるので、重複する説明は一部省略する。
【００１２】
１は本体、２はその元部に備わった連結部である。2aは本体１の先端部に備わった保持部を示し、３は本体１と一体形成の締着筒で、半径方向に弾性変形可能に構成してあり、内部は被保持物を挿入する為の差込孔４となっている。５は締着筒３の内周面の締着面を示す。７は締着筒３の外周面を示し、連結部２の側が太くなるテーパ状に形成してある。
【００１３】
次に締着筒３の周囲に配設した17は回動筒で、その内周面18は前記外周面７と平行なテーパ状に形成してある。21は締着筒３と回動筒17の間に配設された筒状の案内筒で、周知の如く複数の案内孔22が周方向に形成されて鳥篭状（図３（Ｂ）参照）となっており、各案内孔22には１又は複数のローラ24が夫々回動自在に存置させてある。
それらのローラ24は周知の如く案内筒21の中心軸線に対し、一定の角度を持ったねじれの位置の関係に置かれている。
25、25は案内筒21の先端における内外面に夫々周設した防塵用のゴムシールを示す。
【００１４】
次に係止機構９において、10は上記締着筒３の奥部における外周面７に周設された係合溝を示す。上記係合溝10に対向するローラー案内筒21の後部内周面21aには図２から明らかなように上記係合溝10に達するに十分な長さを備える係合子11を備えさせている。この係合子11としては図１、図２に示されるような係合溝10の内でころころ回る鋼球（ボール）であっても良いし、図３に示されるようにローラー案内筒21の後部内周面21aに対して固定的に周設される固定突出物（例えばサークリップ・バネ力があるＣ型クリック）であってもよい。なお鋼球11はローラー案内筒21の奥部の周方向に設けられる。図３の21dは、ここから内部にサークリップ11を挿入し、そこに存置させる為の孔であるが、鋼球11もここらあたりに位置させる為に二点鎖線で示される位置21fに１又は複数の孔を分散配置し、それら複数個の孔に夫々鋼球11を収め、ローラー案内筒21から抜脱しないようにしてある。
上記係合溝10の軸線28方向の幅Ｗは、ローラー案内筒21が通常の進退移動範囲内、即ち、図１の後退端から図２の前進端までの進退動をすることには係合子11はその移動を妨げるような悪影響を及ぼすことはなく、ローラー案内筒21が前進端に至った場合には上記係合子11が溝端10aに接してローラー案内筒21の前進動を阻止出来るような幅Ｗに設定してある。このような回動筒17とローラー案内筒21とを前進させた刃具装着準備状態（図２（Ａ）参照）においては、ローラー案内筒21の先端21bを締着筒の先端3aより前方に突出させ得るようにしてある。
なお上記一対の係止機構９において、締着筒３と、ローラー案内筒21とにおける係合溝10と係合子11との位置関係は、相対的なものであって、図１、２、３に示されるように締着筒３の側に係合溝10を設けても、図４（Ｃ）に示されるようにローラー案内筒21の内周側に設けても良い。図４（Ｃ）に示される係合子としてのサークリップ11は相対的な関係からして締着筒３の外周に固定されている。
【００１５】
図１、２、３において、12は回動筒17に対してローラー案内筒21が独自に後退するのを防止する為の係合部材を示し、全体は図３（Ｂ）に示されているようにリング状に形成されており、その一部における段部内周面には雌ねじ12bが形成されており、これを回動筒17における対向する段部に設けられている雄ねじ17dに対して螺合させることにより回動筒17に対して一体化させてある。外周端12cは回動筒17の段部外周面に密着させ、内周端12aはローラー案内筒21の後端面21aに対向させ係合部材としての役割を担っている。
係合部材12としては、回動筒17に対してローラー案内筒21が相対的に後退するのを防止する為の部分を有するものであればよいので、図４（Ａ）〜（Ｃ）に示されているように回動筒17の内周面に設けた溝に固定的に装着したサークリップ12dでもよいし、回動筒17に設けた雌ねじ孔17eに対して螺合させた押しねじ状の突出物12e（又は孔に対してかしめ着けた棒体）であっても、ローラー案内筒21の後端面21aに対向させる突出部分を備えるものであれば良い。14は、元部14aに設けた雌ねじを利用して本体１における外周面に設けられている雄ねじ1bに対して螺合固着させてある円筒状のカバーを示し、切り粉や塵が内部に侵入するのを防止する為のものである。13は係合部材12（回動筒17でも良い）の外周面に対して必要に応じて設けたパッキンで、回動筒17が進退動するときにカバーの内周面に摺動するようにしてある。なお図３、図４においてはカバーの図示を省略してあるが必要に応じて装着してもよい。
【００１６】
上記構成のものにあっては、図２（Ａ、Ｂ）に示される前進状態の回動筒17の軸心位置に存在する差込孔４の内部に刃具の元部を差し込む。次に回動筒17を時計回り方向に回動させる。すると上記締着筒３の外周にあるローラーの転動面７の周囲に配置されている多数のローラ24は案内筒21に案内されて上記の如きねじれの位置の関係となった状態で回転する。この為、上記回動筒17を回動させることにより、多数のローラ24は夫々締着筒３の外周の転動面７と回動筒17の内周の転動面18との間で転がりながら外周面７に沿って螺旋状に締着筒３における太径部８の側に向けて後退する。これにより回動筒17も同方向に後退する。このように回動筒17が太径部８の側に向けて図１の状態に向けて後退すると、締着筒３は回動筒17によりローラ24を介して押し縮められることとなり、締着筒３は減径する。その結果締着面５は刃具31の元部外周面に圧接し、これを強く締付ける。
【００１７】
次に刃具31を取り替える場合について説明する。図１の状態から図２（Ａ、Ｂ）に示される前進状態にする為には回動筒17を前回とは逆方向に回す。するとローラー24も逆方向に回動し、回動筒17は前進する。かかる場合係合子11は溝10の内を図２（Ａ、Ｂ）に示される最前進状態に至るまで、ローラー案内筒21と共に何らの障害を受けることなく前進する。最前進状態に至ると係合子11が溝端（溝の側部）10aに当たり、ローラー案内筒21は図２（Ａ、Ｂ）に示される前進状態で停止する。またこれに伴い係合部材12がローラー案内筒21の後端21aに当たり、回動筒17も停止する。この前進状態で刃具を取り替えると良い。なお上記の停止位置についてはゴムシール２５が突出しない位置で止めるのが好ましい状態であるが、切り粉や塵が内部に侵入する恐れのない作業状態において利用される場合は最先端のローラー24aが脱落しない範囲で締着筒先端3aより突出するように、例えば案内筒21に対する鋼球11の装着位置を前後変更させたり、図４（Ｃ）の締付筒３に対するサークリップ11の位置を前後変更させても良い。
【００１８】
上記のように一対の係止機構９をローラー案内筒21の後方に具備させることにより、これらの部品が高速回転中において飛散することのないようになる。
またこのように安全に構成したものであっても、ローラー案内筒21の先端21bは上記のように前進位置において締着筒先端3aよりも突出するが、しかし全体は抜脱しないようになった。
さらに、上記係合溝10と係合子11で構成される一対の係止機構９をローラー案内筒21の後方に具備させることにより、回転筒17、或いは締着筒３の先端に嵩張りのある付属物を設けなくても、即ち、両先端が揃うように構成しても、上記のようにしてローラー案内筒21の抜け止めと共に回動筒17の抜け止めをも出来るようになった。
【００１９】
さらに図２（Ａ、Ｂ）に示される前進状態から明らかなように、ローラー案内筒21の先端は締着筒先端3aよりも大きく突出するので、必然的に最先端のローラー24aも締着筒先端3a位置に前進する。このような状態において刃具を装着し、その後上記したような操作をして回動筒17とローラー案内筒21とを後退させ、刃具締付状態（図１参照）にすると、ローラー案内筒21においてガイドされている複数のローラーの内、最先端のローラー24aの位置は、当然のことながら締着筒の先端3aに近い位置において止まる。
このように最先端のローラー24aの位置が、締着筒の先端3aに近い位置において止まると、締着筒の先端3aの部分における締付力が大きくなる。締着筒の先端3aの部分における締付力が大きくなると、刃具に大きな負荷が掛かった場合でも刃具の芯ぶれを防止することができ、加工精度を向上させることができる。
【００２０】
【発明の効果】
以上のように本願発明は、締着筒の後部側における外周面には、周方向に係合溝を周設し、一方、上記締着筒の後部側外周面に設けられた上記係合溝に対向するローラー案内筒の後部側の内周面には、上記締着筒の後部側外周面に設けられた係合溝内に達するに充分な長さを備える係合子を備えさせ、上記締着筒の後部側外周面に周設された係合溝の上記軸線方向の幅寸法は、ローラー案内筒が通常の進退移動範囲内で進退動することを係合子が妨げることなく、ローラー案内筒が前進端に至った場合には、上記係合子が溝端に接してローラー案内筒が上記前進端の位置から、前進動するのを阻止出来るような幅に設定し、
更に、上記締着筒に対し回動筒を回すことによって上記複数のローラーを転動させて、上記ローラーを保持する為のローラー案内筒と上記回動筒とを軸線方向へ進退移動させるときには、上記係合子が上記締着筒の後部側外周面に設けられた上記係合溝を周方向に移動しながら、かつ、上記締着筒の軸線方向にも上記係合溝を、軸線方向の幅寸法の範囲内で進退移動するようにしたものであるから、
回動筒17とローラー案内筒21とを前進させた刃具装着準備状態において、ローラー案内筒21の先端を締着筒３の先端より前方に向けて充分に突出させ得るようにでき、しかもその突出状態において回動筒17やローラー案内筒21が締着筒３から脱出することのないようにできる特長がある。
【００２１】
これにより本願発明にあっては、前述した従来の保持具の問題点（締付筒３の先端にローラー案内筒21の突出を防止する為の抜止用サークリップ27が装着装着される点に係わる問題点）を解決できるその上に、
【００２２】
回動筒17とローラー案内筒21とを前進させて刃具の装着準備状態にした場合、従来の保持具のように、締付筒３の先端にローラー案内筒21の突出を防止する為の抜止用サークリップ27を設けない構成であるから、
本願発明の場合は、締着筒３の先端面3aは開放されており、その先端面3aの開放により、締着筒３の先端面3aに接触する状態でもって「段付き刃具の段部」を装着することのできる効果もある。
【００２３】
さらに本願発明にあっては、回動筒17とローラー案内筒21とを後退させて刃具締付状態にした場合にローラー案内筒21によってガイドされている複数のローラー24の内、最先端のローラー24aの位置する場所を、締着筒３の先端3aに近い位置にすることができ、締着筒３の先端3aにおける締付力を大きくして利用することができ、刃具における芯ぶれを防止するうえに効果がある。
【００２４】
しかも本願における一対の係止機構９は、ローラー案内筒21の後方の内側に具備させることにより、これが高速回転中において飛散することのないように構成できる効果がある。しかも一対の係止機構９は、ローラー案内筒21の後方の内側に具備させることにより、ローラー案内筒21を利用して回動筒17の抜け止めをも容易に出来るようにすることができる効果もある。
【図面の簡単な説明】
【図１】刃具締め付け状態を示す断面図。
【図２】（Ａ）は刃具の受入を準備する為に回動筒を前進させた状態を示す部分断面図、（Ｂ）は部分拡大図。
【図３】（Ａ）は図２における係止機構の係合子とは異なる係合子の例を示す部分断面図、（Ｂ）は（Ａ）の部材を分解して示す斜視図。
【図４】（Ａ）は図２における係合部材とは異なる係合部材の例を示す部分断面図、（Ｂ）は図２における係合部材とはさらに異なる係合部材の例を示す部分断面図、（Ｃ）は図２における係合部材とは異なる係合部材の例と、図２における係止機構の異なる例を示す部分断面図。
【図５】（Ａ）は従来例において刃具の受入を準備する為に回動筒を前進させた状態を示す断面図。（Ｂ）は従来例の刃具締め付け状態を示す断面図。
【符号の説明】
１・・・本体、２・・・連結部、２ａ・・・保持部、３・・・締着筒、４・・・差込孔、５・・・締着面、９・・・係止機構、１０・・・溝、１１・・・係合子、１２・・・係合部材、１７・・・回動筒、１８・・・内周面、２１・・・案内筒（鳥篭状）、２２・・・案内孔、２４・・・ローラ、２４ａ・・・先頭のローラ群、２５・・・防塵用のゴムシール、３１・・・被保持物31（刃具）。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a known cutting tool such as a drill used in a machine tool or a holding tool configured to hold a workpiece to be processed.
[0002]
[Prior art]
As a conventionally known holding tool, there are those shown in FIG. 5 (see, for example, JP-A-6-285706 and JP-B-7-67641). In FIG. 5, reference numeral 1 denotes a main body, and 2 denotes a connecting portion provided at a base portion thereof, which is a portion that is attached to a spindle of a machine tool. Reference numeral 2a denotes a holding portion provided at the tip of the main body 1. In the holding portion 2a, reference numeral 3 denotes a fastening cylinder integrally formed with the main body 1, and is configured to be elastically deformable in the radial direction, and the inside is an insertion hole 4 for inserting an object to be held. Reference numeral 5 denotes a fastening surface on the inner peripheral surface of the fastening tube 3. 7 shows the outer peripheral surface of the fastening cylinder 3, and it is formed in the taper shape which the connection part 2 side becomes thick. Next, 17 arranged around the fastening cylinder 3 is a rotating cylinder, and its inner peripheral surface 18 is formed in a taper shape parallel to the outer peripheral surface 7. A well-known spanner groove 19 is formed on the outer peripheral surface. Next, 21 is a cylindrical guide cylinder disposed between the fastening cylinder 3 and the rotating cylinder 17, and as is well known, a plurality of guide holes 22 are formed in the circumferential direction to form a birdcage (FIG. 3B). Each guide hole 22 is provided with one or a plurality of rollers 24 rotatably. As is well known, these rollers 24 are placed in a torsional position having a certain angle with respect to the central axis of the guide cylinder 21 (coincident with the central axis of the fastening cylinder 3). As is well known, these rollers 24 are divided into a plurality of roller groups 24a in the circumferential direction of the fastening cylinder 3 (see FIG. 3B). Reference numerals 25 and 26 denote a dust-proof rubber seal and a seal retainer ring which are provided around the tip 3a of the fastening tube 3, and 27 is attached to the outer periphery of the tip of the fastening tube 3 so that the guide tube 21 is removed. The circlip for retaining is shown in order to prevent the above. Reference numerals 25 'and 26' denote a dust-proof rubber seal and a retaining circlip which are fixed to the inner periphery of the rear end of the rotating cylinder 17 to prevent the guide cylinder 21 from being pulled out.
[0003]
Next, an operation of holding the object to be held 31 such as a cutting tool (which may be a workpiece) using the holding tool having the above configuration will be described. The base part of the cutting tool 31 is inserted into the insertion hole 4 existing at the axial center position of the rotating cylinder 17 in the forward movement state shown in FIG. Next, the rotating cylinder 17 is rotated clockwise. Then, the large number of rollers 24 are guided by the guide tube 21 and rotate in the state of the twisted position as described above. Therefore, by rotating the rotating cylinder 17, a large number of rollers 24 roll between the outer rolling surface 7 of the fastening cylinder 3 and the inner rolling surface 18 of the rotating cylinder 17. However, it retreats spirally along the outer peripheral surface 7 toward the large diameter portion 8 side of the fastening cylinder 3. As a result, the rotating cylinder 17 is also retracted in the same direction. When the rotating cylinder 17 is retracted to the state of FIG. 5B toward the large diameter portion 8 in this way, the fastening cylinder 3 is compressed by the rotating cylinder 17 via the roller 24. The fastening cylinder 3 is reduced in diameter. As a result, the fastening surface 5 comes into pressure contact with the outer peripheral surface of the cutting tool and tightens it firmly.
In the state in which the object to be held 31 is fastened and held as described above, the fastening cylinder 3 and the object to be held 31 are rotated by rotating the main body 1 and machined as is well known by the object to be held (example) Cutting).
[0004]
[Problems to be solved by the invention]
In this conventional holder, the plurality of rollers are rolled by rotating the rotating cylinder 17 with respect to the fastening cylinder 3, and the roller guide cylinder 21 for holding the rollers; Thus, there is an advantage that the fastening cylinder 3 can be moved forward and backward in the axial direction to increase or decrease the diameter of the fastening cylinder 3, whereby the cutting tool can be tightened and loosened on the inner peripheral surface and provided for machining.
[0005]
However, since a circlip 27 for preventing the roller guide cylinder 21 from protruding is attached to the tip of the clamping cylinder 3, the roller guide is used when the cutter is pulled out by loosening the tightening of the clamping cylinder 3. The forward end positions of the cylinder 21 and the rotating cylinder 17 are limited. When the forward end positions of the roller guide cylinder 21 and the rotary cylinder 17 are restricted in this way, the most advanced position of the roller 24 is necessarily the most advanced position 3a of the clamping cylinder 3, as is apparent from FIG. It will be located more rearward.
[0006]
Then, in the state where the cutting tool is mounted with the rotating cylinder 17 and the roller guide cylinder 21 retracted, as shown in FIG. 5B, the position of the roller 24 at the most advanced position is the highest position of the clamping cylinder 3. The position is retracted considerably rearward from the tip position 3a (position retracted by the dimension L).
When the cutting tool 31 is tightened in such a tightened state, there is a problem that it is difficult to exert a sufficient tightening force in a section that is retracted by a dimension L from the most distal position 3a of the tightening cylinder 3.
[0007]
Further, as shown in FIG. 5 (B), the main body in the state where the accessory for preventing the protrusion of the roller guide cylinder 21 is present at the distal end of the clamping cylinder 3 or disposed at the distal end of the rotating cylinder 17. When 1 is rotated at a high speed, an accessory for preventing the roller guide cylinder 21 from protruding, such as a circlip 27, escapes and scatters due to centrifugal force, causing a problem that causes unexpected harm to workers.
[0008]
In order to solve the above-mentioned problems, there is a method in which a cap is attached to the most advanced position 3a of the fastening cylinder 3 and screwed to the most advanced position 3a (for example, JP-A-11-11). 77412). However, when configured in this way, there arises a problem that the above-mentioned cap gives resistance to the most advanced reduction action of the fastening cylinder 3.
Furthermore, it is conceivable to attach an accessory for preventing the roller guide cylinder 21 from protruding to the tip 17a of the rotating cylinder 17. However, when such an accessory is attached, the accessory becomes larger from the tip 3a of the clamping cylinder 3. There arises a problem that causes troubles in mounting of the blade tool that protrudes and has a hook.
[0009]
The purpose of the present application is to roll a plurality of rollers by rotating the rotating cylinder with respect to the fastening cylinder, and to move the roller guiding cylinder for holding the roller and the rotating cylinder back and forth in the axial direction. An object of the present invention is to provide a holder that can be provided for machining by increasing or decreasing the diameter of the fastening cylinder, thereby allowing the cutter to be tightened and loosened on the inner peripheral surface.
Another object is to allow the tip of the roller guide tube to protrude forward from the tip of the fastening tube in the cutting tool mounting preparation state in which the rotating tube and the roller guide tube are advanced (see FIG. 2A). It is intended to provide a holder.
Another object is that the cutting-edge roller position of a plurality of rollers guided by the roller guide tube is fastened in the state of tightening the blade (see FIG. 1) in which the rotating tube and the roller guide tube are retracted. It is an object of the present invention to provide a holder that stops at a position close to the tip of the cylinder and has a large clamping force at the tip of the fastening cylinder.
Another object is to prevent the rotating cylinder and the roller guide cylinder from escaping even if the tip of the roller guide cylinder can be protruded forward from the tip of the fastening cylinder as described above. It is intended to provide a holder.
Another object is to provide a pair of locking mechanisms behind the roller guide cylinder so that it does not scatter during high-speed rotation, and even so safely. An object of the present invention is to provide a holder that prevents the roller guide tube from being pulled out even if the front end of the roller guide tube protrudes from the front end of the fastening tube at the forward movement position.
Another object is to prevent the roller guide tube from coming off by providing a pair of locking mechanisms on the inner side behind the roller guide tube. It is an object of the present invention to provide a holder that can omit the accessory for preventing the guide tube 21 from protruding and that can also prevent the rotating tube from coming off.
Other objects and advantages will be readily apparent from the drawings and the following description associated therewith.
[0010]
[Means for Solving the Problems]
The holder in the present invention is a cylindrical shape in which an insertion hole for an object to be held whose front end is open is formed on the inner side, a roller rolling surface is formed on the outer peripheral surface, and is elastically deformable in the radial direction. A fastening tube of
A rotating cylinder disposed so as to be relatively rotatable around the fastening cylinder;
A plurality of rollers disposed between the outer peripheral surface of the fastening cylinder and the inner peripheral surface of the rotating cylinder and a roller guide cylinder for holding those rollers;
The plurality of rollers are rolled by rotating the rotating cylinder with respect to the fastening cylinder, and the roller guiding cylinder for holding the roller and the rotating cylinder are moved back and forth in the axial direction to move the fastening cylinder. In a holder that increases or decreases the diameter and allows the object to be held to be tightened and loosened by its inner peripheral surface,
On the outer peripheral surface on the rear side of the fastening tube, an engagement groove is provided in the circumferential direction,
On the other hand, on the inner peripheral surface of the rear side of the roller guide cylinder facing the engaging groove provided on the outer peripheral surface of the fastening cylinder, the engagement provided on the outer peripheral surface of the fastening cylinder Having an engagement element with a length sufficient to reach into the groove;
The width dimension in the axial direction of the engaging groove provided on the outer peripheral surface of the rear side of the fastening cylinder is such that the engagement element does not prevent the roller guide cylinder from moving forward and backward within a normal forward / backward movement range. When the guide tube reaches the forward end, the width is set such that the engagement element contacts the groove end and the roller guide tube can be prevented from moving forward from the position of the forward end.
When rotating the rotating cylinder relative to the fastening cylinder to roll the plurality of rollers, the roller guide cylinder for holding the roller and the rotating cylinder are moved forward and backward in the axial direction. While the connector moves in the circumferential direction on the engagement groove provided on the outer peripheral surface of the fastening cylinder, the engagement groove is also moved in the axial direction of the fastening cylinder with the width dimension in the axial direction. It is designed to move forward and backward within the range.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, drawings showing embodiments of the present invention will be described. In the description of FIG. 1 to FIG. 4, the functions, properties, characteristics, etc. of the components, members, etc. using the same reference numerals as those in FIG. 5 described above are matters relating to the description of the new member configurations, combinations, etc. added below. Except for the above, it can be understood that the above description is the same as the above description, and a part of the overlapping description is omitted.
[0012]
Reference numeral 1 denotes a main body, and 2 denotes a connecting portion provided at a base portion thereof. 2a is a holding part provided at the tip of the main body 1, 3 is a fastening tube formed integrally with the main body 1, and is configured to be elastically deformable in the radial direction, and the inside is used for inserting an object to be held. It is an insertion hole 4. Reference numeral 5 denotes a fastening surface on the inner peripheral surface of the fastening tube 3. 7 shows the outer peripheral surface of the fastening cylinder 3, and it is formed in the taper shape which the connection part 2 side becomes thick.
[0013]
Next, 17 arranged around the fastening cylinder 3 is a rotating cylinder, and its inner peripheral surface 18 is formed in a taper shape parallel to the outer peripheral surface 7. 21 is a cylindrical guide cylinder disposed between the fastening cylinder 3 and the rotating cylinder 17, and as is well known, a plurality of guide holes 22 are formed in the circumferential direction to form a birdcage (see FIG. 3B). Each guide hole 22 is provided with one or a plurality of rollers 24 rotatably.
As is well known, these rollers 24 are placed in a relationship of a twisted position having a certain angle with respect to the central axis of the guide tube 21.
Reference numerals 25 and 25 denote dust-proof rubber seals provided around the inner and outer surfaces at the tip of the guide tube 21, respectively.
[0014]
Next, in the locking mechanism 9, reference numeral 10 denotes an engagement groove provided around the outer peripheral surface 7 in the inner part of the fastening cylinder 3. The rear inner peripheral surface 21a of the roller guide cylinder 21 facing the engagement groove 10 is provided with an engagement element 11 having a length sufficient to reach the engagement groove 10 as is apparent from FIG. The engaging element 11 may be a steel ball (ball) that rolls in the engaging groove 10 as shown in FIGS. 1 and 2, or the rear part of the roller guide cylinder 21 as shown in FIG. It may be a fixed protrusion (for example, a C-click with a circlip or spring force) fixedly provided around the inner peripheral surface 21a. The steel ball 11 is provided in the circumferential direction of the inner part of the roller guide tube 21. 21d in FIG. 3 is a hole for inserting the circlip 11 into the inside from this position and placing it there, but in order to position the steel ball 11 around here, the position 21f indicated by a two-dot chain line is 1 or A plurality of holes are dispersedly arranged, and the steel balls 11 are respectively stored in the plurality of holes so as not to be removed from the roller guide cylinder 21.
The width W in the direction of the axis 28 of the engagement groove 10 is determined so that the roller guide cylinder 21 is engaged within the normal forward / backward movement range, that is, the forward / backward movement from the backward end of FIG. 1 to the forward end of FIG. 11 does not adversely affect its movement, and when the roller guide cylinder 21 reaches the forward end, the engagement element 11 comes into contact with the groove end 10a so that the forward movement of the roller guide cylinder 21 can be prevented. The width W is set. In such a cutting tool mounting preparation state (see FIG. 2A) in which the rotating cylinder 17 and the roller guide cylinder 21 are advanced, the tip 21b of the roller guide cylinder 21 projects forward from the tip 3a of the fastening cylinder. It can be made to be able to.
In the pair of locking mechanisms 9, the positional relationship between the engagement groove 10 and the engagement element 11 in the fastening cylinder 3 and the roller guide cylinder 21 is relative, and is shown in FIGS. As shown in FIG. 4, the engagement groove 10 may be provided on the fastening tube 3 side, or may be provided on the inner peripheral side of the roller guide tube 21 as shown in FIG. The circlip 11 as an engaging member shown in FIG. 4C is fixed to the outer periphery of the fastening cylinder 3 in a relative relationship.
[0015]
In FIGS. 1, 2, and 3, reference numeral 12 denotes an engaging member for preventing the roller guide cylinder 21 from retreating independently with respect to the rotating cylinder 17, and the whole is shown in FIG. 3 (B). The internal thread 12b is formed on the inner peripheral surface of a part of the step part, and this is screwed to the external thread 17d provided on the opposing step part of the rotating cylinder 17. By combining them, the rotating cylinder 17 is integrated. The outer peripheral end 12c is brought into close contact with the outer peripheral surface of the step portion of the rotating cylinder 17, and the inner peripheral end 12a is opposed to the rear end surface 21a of the roller guide cylinder 21 and serves as an engaging member.
As the engaging member 12, any member may be used as long as it has a portion for preventing the roller guide tube 21 from retreating relative to the rotating tube 17, and therefore, as shown in FIGS. As shown, a circlip 12d fixedly mounted in a groove provided on the inner peripheral surface of the rotating cylinder 17 or a push screw screwed into a female screw hole 17e provided in the rotating cylinder 17 may be used. Even if it is the shape-like protrusion 12e (or the rod body crimped with respect to the hole), it is sufficient if it has a protruding portion facing the rear end surface 21a of the roller guide tube 21. Reference numeral 14 denotes a cylindrical cover which is screwed and fixed to a male screw 1b provided on the outer peripheral surface of the main body 1 by using a female screw provided on the base portion 14a, and chips and dust enter the inside. It is for preventing it from doing. 13 is a packing provided as necessary to the outer peripheral surface of the engaging member 12 (or the rotating cylinder 17), and slides on the inner peripheral surface of the cover when the rotating cylinder 17 moves forward and backward. It is. 3 and 4, the illustration of the cover is omitted, but it may be mounted as necessary.
[0016]
In the case of the above configuration, the base part of the cutting tool is inserted into the insertion hole 4 existing at the axial center position of the rotating cylinder 17 in the forward movement state shown in FIGS. Next, the rotating cylinder 17 is rotated clockwise. Then, a large number of rollers 24 arranged around the rolling surface 7 of the roller on the outer periphery of the fastening cylinder 3 are guided by the guide cylinder 21 and rotate in the state of the twisted position as described above. . Therefore, by rotating the rotating cylinder 17, a large number of rollers 24 roll between the outer rolling surface 7 of the fastening cylinder 3 and the inner rolling surface 18 of the rotating cylinder 17. However, it retreats spirally along the outer peripheral surface 7 toward the large diameter portion 8 side of the fastening tube 3. As a result, the rotating cylinder 17 is also retracted in the same direction. In this way, when the rotating cylinder 17 is retracted toward the state of FIG. 1 toward the large diameter portion 8, the fastening cylinder 3 is compressed by the rotating cylinder 17 via the roller 24. The cylinder 3 is reduced in diameter. As a result, the fastening surface 5 comes into pressure contact with the outer peripheral surface of the base portion of the cutting tool 31 and strongly tightens it.
[0017]
Next, a case where the blade 31 is replaced will be described. In order to change from the state shown in FIG. 1 to the forward state shown in FIGS. 2A and 2B, the rotating cylinder 17 is rotated in the direction opposite to the previous time. Then, the roller 24 also rotates in the reverse direction, and the rotating cylinder 17 moves forward. In such a case, the engaging element 11 moves forward without any obstruction with the roller guide cylinder 21 until reaching the most advanced state shown in FIGS. 2A and 2B. When the most advanced state is reached, the engaging element 11 hits the groove end (side portion of the groove) 10a, and the roller guide cylinder 21 stops in the advanced state shown in FIGS. Accordingly, the engaging member 12 hits the rear end 21a of the roller guide cylinder 21, and the rotating cylinder 17 also stops. It is better to replace the cutting tool in this advanced state. It is preferable to stop the rubber seal 25 at a position where the rubber seal 25 does not protrude. However, the cutting-edge roller 24a drops off when used in a working state where there is no risk of chips or dust entering the inside. For example, the mounting position of the steel ball 11 with respect to the guide cylinder 21 is changed back and forth so that it protrudes from the fastening cylinder tip 3a within the range not to be changed, or the position of the circlip 11 with respect to the fastening cylinder 3 in FIG. You may let them.
[0018]
By providing the pair of locking mechanisms 9 behind the roller guide cylinder 21 as described above, these components are prevented from scattering during high-speed rotation.
Even in such a safe configuration, the tip 21b of the roller guide tube 21 protrudes from the fastening tube tip 3a at the forward movement position as described above, but the whole is not pulled out. .
Further, by providing a pair of locking mechanisms 9 composed of the engagement groove 10 and the engagement element 11 behind the roller guide cylinder 21, the tip of the rotary cylinder 17 or the fastening cylinder 3 is bulky. Even if no accessory is provided, that is, both ends are aligned, the roller guide cylinder 21 can be prevented from coming off and the rotating cylinder 17 can be prevented from coming off as described above.
[0019]
Further, as is clear from the forward state shown in FIGS. 2A and 2B, the tip of the roller guide tube 21 protrudes larger than the fastening tube tip 3a, so that the most advanced roller 24a is necessarily a fastening tube. Advance to the tip 3a position. In such a state, when the cutting tool is mounted, and then the operation as described above is performed to retract the rotating cylinder 17 and the roller guide cylinder 21 and the cutting tool is tightened (see FIG. 1), the roller guide cylinder 21 Of the plurality of guided rollers, the position of the most advanced roller 24a naturally stops at a position close to the tip 3a of the fastening tube.
Thus, when the position of the most advanced roller 24a stops at a position close to the front end 3a of the fastening tube, the tightening force at the front end 3a portion of the fastening tube increases. When the tightening force at the tip 3a portion of the fastening cylinder is increased, it is possible to prevent runout of the cutting tool even when a large load is applied to the cutting tool, thereby improving processing accuracy.
[0020]
【The invention's effect】
As described above, according to the present invention, the engaging groove is provided in the circumferential direction on the outer peripheral surface on the rear side of the fastening cylinder, while the engaging groove provided on the rear side outer peripheral surface of the fastening cylinder. An engagement element having a length sufficient to reach an engagement groove provided in the rear outer peripheral surface of the fastening cylinder is provided on the inner peripheral surface of the rear side of the roller guide cylinder opposite to the fastening guide cylinder. The width dimension in the axial direction of the engaging groove provided on the outer peripheral surface of the rear side of the landing tube is such that the roller guide tube does not prevent the engaging member from moving forward and backward within the normal forward / backward movement range. Is set to such a width as to prevent the roller guide tube from moving forward from the position of the advance end by contacting the end of the groove with the engagement element,
Further, when the plurality of rollers are rolled by rotating the rotating cylinder with respect to the fastening cylinder, the roller guide cylinder for holding the roller and the rotating cylinder are moved forward and backward in the axial direction. While the engagement element moves in the circumferential direction on the engagement groove provided on the outer peripheral surface on the rear side of the fastening cylinder, the engagement groove is also moved in the axial direction in the axial direction of the fastening cylinder. Because it is designed to move forward and backward within the dimensions,
In a state where the rotating cylinder 17 and the roller guide cylinder 21 are advanced, the tip of the roller guide cylinder 21 can be sufficiently protruded forward from the front end of the fastening cylinder 3, and the protrusion In this state, the rotating cylinder 17 and the roller guide cylinder 21 can be prevented from escaping from the fastening cylinder 3.
[0021]
Thus, in the present invention, there is a problem with the above-mentioned conventional holding tool (related to the fact that the retaining circlip 27 for preventing the roller guide cylinder 21 from protruding from the tip of the fastening cylinder 3 is mounted and mounted. In addition to solving the problem)
[0022]
When the rotating cylinder 17 and the roller guide cylinder 21 are moved forward to prepare for the attachment of the cutting tool, the stopper for preventing the roller guide cylinder 21 from protruding at the tip of the clamping cylinder 3 as in the conventional holder. Because it is a configuration that does not provide the circlip 27 for
In the case of the present invention, the distal end surface 3a of the fastening cylinder 3 is open, and the "stepped portion of the stepped blade" is in contact with the distal end surface 3a of the fastening cylinder 3 by opening the distal end face 3a. There is also an effect that can be worn.
[0023]
Further, in the present invention, the state-of-the-art roller among the plurality of rollers 24 guided by the roller guide tube 21 when the rotating tube 17 and the roller guide tube 21 are moved backward to enter the blade tool tightening state. The position where 24a is located can be close to the tip 3a of the fastening tube 3, and the tightening force at the tip 3a of the fastening tube 3 can be increased to prevent runout in the cutting tool. It is effective in doing.
[0024]
Moreover, by providing the pair of locking mechanisms 9 in the present application inside the rear side of the roller guide cylinder 21, there is an effect that the pair of locking mechanisms 9 can be configured not to be scattered during high-speed rotation. In addition, by providing the pair of locking mechanisms 9 on the inner side behind the roller guide cylinder 21, the roller guide cylinder 21 can be used to easily prevent the rotating cylinder 17 from coming off. There is also.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which a blade is tightened.
FIG. 2A is a partial cross-sectional view showing a state in which a rotating cylinder is advanced to prepare for receiving a cutting tool, and FIG. 2B is a partial enlarged view.
3A is a partial cross-sectional view showing an example of an engaging member different from the engaging member of the locking mechanism in FIG. 2, and FIG. 3B is an exploded perspective view showing the member of FIG.
4A is a partial cross-sectional view showing an example of an engaging member different from the engaging member in FIG. 2, and FIG. 4B is a part showing an example of an engaging member further different from the engaging member in FIG. Sectional drawing, (C) is a partial sectional view showing an example of an engaging member different from the engaging member in FIG. 2 and a different example of the locking mechanism in FIG.
FIG. 5A is a cross-sectional view showing a state in which a rotating cylinder is advanced in order to prepare for receiving a cutting tool in a conventional example. (B) is sectional drawing which shows the cutting tool clamping state of a prior art example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main body, 2 ... Connection part, 2a ... Holding part, 3 ... Fastening cylinder, 4 ... Insertion hole, 5 ... Fastening surface, 9 ... Locking Mechanism: 10 ... groove, 11 ... engaging element, 12 ... engaging member, 17 ... rotating cylinder, 18 ... inner peripheral surface, 21 ... guide cylinder (birdcage-like), 22 ... guide hole, 24 ... roller, 24a ... first roller group, 25 ... rubber-proof rubber seal, 31 ... held object 31 (blade).

Claims

An insertion hole for the object to be held whose front end side is opened on the inner side, a rolling surface of the roller is formed on the outer peripheral surface, and a cylindrical fastening cylinder that is elastically deformable in the radial direction;
A rotating cylinder disposed so as to be relatively rotatable around the fastening cylinder;
A plurality of rollers disposed between the outer peripheral surface of the fastening cylinder and the inner peripheral surface of the rotating cylinder and a roller guide cylinder for holding those rollers;
The plurality of rollers are rolled by rotating the rotating cylinder with respect to the fastening cylinder, and the roller guiding cylinder for holding the roller and the rotating cylinder are moved back and forth in the axial direction to move the fastening cylinder. In a holder that increases or decreases the diameter and allows the object to be held to be tightened and loosened by its inner peripheral surface,
On the outer peripheral surface on the rear side of the fastening tube, an engagement groove is provided in the circumferential direction,
On the other hand, on the inner peripheral surface of the rear side of the roller guide cylinder facing the engaging groove provided on the outer peripheral surface of the fastening cylinder, the engagement provided on the outer peripheral surface of the fastening cylinder Having an engagement element with a length sufficient to reach into the groove;
The width dimension in the axial direction of the engaging groove provided on the outer peripheral surface of the rear side of the fastening cylinder is such that the engagement element does not prevent the roller guide cylinder from moving forward and backward within a normal forward / backward movement range. When the guide tube reaches the forward end, the width is set such that the engagement element contacts the groove end and the roller guide tube can be prevented from moving forward from the position of the forward end.
When rotating the rotating cylinder relative to the fastening cylinder to roll the plurality of rollers, the roller guide cylinder for holding the roller and the rotating cylinder are moved forward and backward in the axial direction. While the connector moves in the circumferential direction on the engagement groove provided on the outer peripheral surface of the fastening cylinder, the engagement groove is also moved in the axial direction of the fastening cylinder with the width dimension in the axial direction. A holder characterized by moving forward and backward within a range.

An insertion hole for the object to be held whose front end side is opened on the inner side, a rolling surface of the roller is formed on the outer peripheral surface, and a cylindrical fastening cylinder that is elastically deformable in the radial direction;
A rotating cylinder disposed so as to be relatively rotatable around the fastening cylinder;
A plurality of rollers disposed between the outer peripheral surface of the fastening cylinder and the inner peripheral surface of the rotating cylinder and a roller guide cylinder for holding those rollers;
The plurality of rollers are rolled by rotating the rotating cylinder with respect to the fastening cylinder, and the roller guiding cylinder for holding the roller and the rotating cylinder are moved back and forth in the axial direction to move the fastening cylinder. In a holder that increases or decreases the diameter and allows the object to be held to be tightened and loosened by its inner peripheral surface,
On the inner peripheral surface on the rear side of the roller guide cylinder, an engagement groove is provided in the circumferential direction,
On the other hand, on the outer peripheral surface of the fastening tube facing the engaging groove provided on the rear inner peripheral surface of the roller guide tube, the engagement provided on the rear inner peripheral surface of the roller guide tube is provided. Provide an engagement element with a sufficient length to reach the groove,
Width of the axial direction of the circumferentially provided by the engaging groove in the rear side inner peripheral surface of the roller guide tube without interfering the engaging member that the roller guide barrel moves back and forth within the normal reciprocating movement range, When the roller guide tube reaches the forward end, the width of the roller guide tube is set so as to prevent the roller guide tube from moving forward from the position of the forward end by contacting the groove end,
When rotating the rotating cylinder relative to the fastening cylinder to roll the plurality of rollers, the roller guide cylinder for holding the roller and the rotating cylinder are moved forward and backward in the axial direction. While the lever moves relative to the engagement groove provided on the inner peripheral surface of the rear side of the roller guide tube in the circumferential direction, the engagement groove is also formed in the axial direction of the roller guide tube with the width in the axial direction. A holding tool which moves forward and backward within a range of dimensions.

The holder according to claim 1 or 2, wherein the engagement element is a rotatable sphere.

The holder according to claim 1, wherein the engagement element is a fixed protrusion.