JP3812475B2

JP3812475B2 - Blade replacement type cutting tool

Info

Publication number: JP3812475B2
Application number: JP2002086002A
Authority: JP
Inventors: 勝彦佐藤; 隆広佐藤
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2002-03-26
Filing date: 2002-03-26
Publication date: 2006-08-23
Anticipated expiration: 2022-03-26
Also published as: JP2003285206A

Description

【０００１】
【発明の属する技術分野】
本発明は、刃部が着脱可能に工具本体に装着される刃部交換式切削工具に関するものである。
【０００２】
【従来の技術】
従来、この種の刃部交換式切削工具の一例として、例えば、図５に示すような刃部交換式切削工具１０があり、これは、軸線Ｏ回りに回転される工具本体１１に対して、図示せぬ刃部が着脱自在に装着されて固定されるものである。
工具本体１１には、その先端面１１Ａから後端側に向かって取付孔１２が穿設されており、取付孔１２は、軸線Ｏ方向の後端側（図中左側）に向かうにしたがい内径が漸次縮径する略円錐台孔状のテーパ孔１３を有している。
【０００３】
そして、取付孔１２内に、軸線Ｏ方向の後端側に向かうにしたがい外径が漸次縮径する略円錐台状のテーパ部２１を有する締結部材２０が収容されていて、この締結部材２０には、その先端面２０Ａから軸線Ｏ方向の後端側に向かって締結孔２２が穿設されているとともに、先端面２０Ａから軸線Ｏ方向の後端側及び後端面２０Ｂから軸線Ｏ方向の先端側へ向かって複数のスリット２３が切り込まれている。
また、工具本体１１の先端部分には、上記の取付孔１２内に収容された締結部材２０が抜け落ちないように、略円筒状をなすキャップ３０が取り付けられており、工具本体１１の先端部分の外周面に形成された雄ねじ部１４に対してキャップ３０の雌ねじ部３１がねじ込まれている。
【０００４】
刃部を工具本体１１に装着する際には、刃部の後端側部分を取付孔１２内に収容されている締結部材２０の締結孔２２に挿入した後、キャップ３０をねじ込んでいくことにより、このキャップ３０によって締結部材２０が押圧され、締結部材２０が工具本体１１に対して軸線Ｏ方向の後端側へ相対移動させられていく。
すると、締結部材２０のテーパ部２１の外周面が取付孔１２のテーパ孔１３の内周面によって押圧され、締結孔２２が収縮して刃部の後端側部分が締め付けられて、この刃部が工具本体１１に着脱可能に装着されるのである。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記のような刃部交換式切削工具１０では、取付孔１２のテーパ孔１３が、軸線Ｏ方向の後端側に向かうにしたがい漸次縮径するようになっているため、工具本体１１の先端側部分を軸線Ｏ方向の先端側に向かうにしたがい外径が漸次縮径するような先細り形状にしようとすると、どうしても、軸線Ｏ方向の先端側に向かうにしたがい肉薄となって、工具本体１１の剛性を著しく低下させてしまうので、工具本体１１の先端側部分をより小径化することができなかった。
【０００６】
本発明は、上記課題に鑑みてなされたもので、工具本体をその剛性を低めることなく先細り形状とすることができる刃部交換式切削工具を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記の課題を解決して、このような目的を達成するために、本発明による刃部交換式切削工具は、少なくとも一つの切刃を備えた切削部を有する刃部の後端側部分が、工具本体に穿設された取付孔に挿入されて、この刃部が着脱可能に装着される刃部交換式切削工具であって、前記取付孔は、前記工具本体の軸線方向の後端側に向かうにしたがい内径が漸次拡径する略円錐台孔状のテーパ孔を有し、かつ、この取付孔内に、前記軸線方向の後端側に向かうにしたがい外径が漸次拡径する略円錐台状のテーパ部を有する締結部材が収容され、前記締結部材には、その先端面から前記軸線方向の後端側に向かって締結孔が穿設されているとともに、前記先端面から前記軸線方向の後端側に向かってスリットが切り込まれていて、前記刃部の後端側部分は雄ねじ部を有し、前記締結孔は雌ねじ部を有していて、前記刃部の後端側部分の雄ねじ部が前記締結孔の雌ねじ部にねじ込まれることにより、前記締結部材が前記工具本体に対して前記軸線方向の先端側に相対移動させられて、前記締結部材のテーパ部の外周面が前記取付孔のテーパ孔の内周面によって押圧され、前記締結孔が収縮して前記刃部の後端側部分が締め付けられて、前記刃部が着脱可能に装着されることを特徴とするものである。
このような構成とされた本発明の刃部交換式切削工具では、取付孔のテーパ孔及び締結部材のテーパ部が軸線方向の後端側に向かうにしたがい漸次拡径しているため、締結部材が工具本体に対して軸線方向の先端側に相対移動させられることにより、締結部材の締結孔が収縮して刃部の後端側部分を強固に締め付けることができる。
しかも、取付孔のテーパ孔が、軸線方向の後端側に向かうにしたがい漸次拡径させられていることにより、たとえ、工具本体の先端側部分を軸線方向の先端側に向かうにしたがい縮径するような先細り形状にしたとしても、必要以上に肉薄となることがなく、工具本体の剛性を低めてしまうことがない。
【０００８】
また、前記刃部の後端側部分は雄ねじ部を有し、前記締結孔は雌ねじ部を有していて、前記刃部の後端側部分の雄ねじ部が前記締結孔の雌ねじ部にねじ込まれることにより、前記締結部材が前記工具本体に対して前記軸線方向の先端側に相対移動させられるため、刃部の後端側部分に形成された雄ねじ部を、締結孔の雌ねじ部にねじ込んでいくだけで、容易に刃部の後端側部分を締結することが可能となる。
さらには、締結部材の締結孔によって刃部の後端側部分を締結できることに加えて、ねじ同士の螺合によっても刃部の締結を行うことができるので、より強固に刃部を締結して、刃部の装着状態の安定化を図ることが可能となる。
【００１０】
【発明の実施の形態】
以下、本発明の実施形態を添付した図面を参照しながら説明する。
図１及び図２は本発明の実施形態による刃部交換式切削工具を示す一部破断側面図、図３は同刃部交換式切削工具の刃部を示す側面図、図４（ａ）は同刃部交換式切削工具の締結部材を示す側面図、（ｂ）は同締結部材の先端面図、（ｃ）は同締結部材の後端面図である。
【００１１】
本第１実施形態による刃部交換式切削工具１００は、図１及び図２に示すように、軸線Ｏ回りに回転させられる工具本体１１０と、この工具本体１１０に着脱自在に装着されて固定される刃部１３０と、刃部１３０を締結して工具本体１１０に装着するために用いる締結部材１４０とからなるものである。
【００１２】
工具本体１１０は、図１及び図２に示すように、例えば鋼からなり、軸線Ｏを中心とする略円柱状に形成されているとともに、その先端面１１１から軸線Ｏ方向の後端側（図中右側）に向けて、軸線Ｏを中心とした取付孔１１２が穿設されている。
また、工具本体１１０の先端側部分は、軸線Ｏ方向の先端側（図中左側）に向かうにしたがい外径が一定の勾配で漸次縮径していくようなテーパ面１１０Ａを有していて、先細り形状となっている。
【００１３】
取付孔１１２は、工具本体１１０の先端面１１１に開口するとともに軸線Ｏ方向の後端側に向かうにしたがい内径が一定の勾配で漸次拡径していく略円錐台孔状をなすテーパ孔１１３と、このテーパ孔１１３の後端側に滑らかに連なるとともに一定の内径で軸線Ｏ方向の後端側へ延びる略円柱孔状をなす収納孔１１４と、この収納孔１１４の後端側に連なるとともに工具本体１１０の後端面１１６に開口する雌ねじ部１１５とから構成されている。
なお、取付孔１１２のテーパ孔１１３…は、その片角でのテーパ角度θが、２〜２５゜の範囲に設定されている。
【００１４】
そして、この取付孔１１２の雌ねじ部１１５に対して、略円柱状をなす固定ボルト１２０（固定部材）の後端側部分に位置する雄ねじ部１２１が、軸線Ｏ方向の先端側へ向かってねじ込まれており、かつ、固定ボルト１２０の先端側部分１２２が取付孔１１２の収納孔１１４内に収容されている。
また、固定ボルト１２０の先端面１２３における径方向外方側の部分には、軸線Ｏ方向の先端側に突出する少なくとも一つ（例えば３つ）の凸部１２４…が周方向で略等間隔に形成されている一方、固定ボルト１２０の後端面１２５には、六角穴１２６が形成されている。
【００１５】
刃部１３０は、図３に示すように、例えば超硬合金からなり、少なくとも一つの切刃が最先端に形成された切削部１３１と、この切削部１３１の後端側に段差部を経て連なる略円柱状の後端側部分１３２とから構成されて、軸線Ｏを中心として形成されている。
また、刃部１３０の後端側部分１３２における後端部分の外周面には雄ねじ部１３３が形成されている。
【００１６】
ここで、刃部１３０の切削部１３１について詳述すると、軸線Ｏに関して互いに反対側に位置するようにして、軸線Ｏ方向の後端側に向かうにしたがい工具回転方向Ｔの後方側に向かってねじれる一対の切屑排出溝が形成されており、これら切屑排出溝における外周側稜線部に外周切刃１３１Ａ，１３１Ａが形成されている。
また、一対の切屑排出溝における工具回転方向Ｔの前方側を向く壁面の先端側部分がすくい面とされるとともに、このすくい面と先端逃げ面との交差稜線部に、刃部１３０の最先端をなし、かつ、軸線Ｏを挟んで互いに反対側に位置して軸線Ｏ近傍から外周側へ向かって延びる一対の先端切刃１３１Ｂ，１３１Ｂが形成されている。
【００１７】
さらに、この切削部１３１において、一対の外周切刃１３１Ａ，１３１Ａが形成されている部分よりも後端側の部分は、略円板状をなすとともに、その外周面が切り欠かれることにより、軸線Ｏに関して互いに反対側に位置して互いに平行となるような一対の平坦面１３１Ｃ，１３１Ｃが形成されている。
ここで、切削部１３１の後端側に段差部を経て後端側部分１３２が連なっていることから、この切削部１３１には、後端側部分１３２の外周面から屹立して切削部１３１の外周面に交差するような軸線Ｏ方向の後端側を向く壁面１３１Ｄが形成されている。
【００１８】
締結部材１４０は、図４に示すように、軸線Ｏ方向の後端側に向かうにしたがい外径が一定の勾配で漸次拡径していく略円錐台状をなすテーパ部１４１と、このテーパ部１４１の後端側に滑らかに連なるとともに一定の外径で軸線Ｏ方向の後端側へ延びる略円柱状をなす円柱部１４２とから構成されて、軸線Ｏを中心として形成されている。
なお、締結部材１４０のテーパ部１４１は、その片角でのテーパ角度θが、取付孔１１２のテーパ孔１１３…のテーパ角度θと同じ値（２〜２５゜）に設定されている。
【００１９】
また、締結部材１４０には、その先端面１４３から軸線Ｏ方向の後端側に向けて、軸線Ｏを中心とした締結孔１４５が穿設されており、この締結孔１４５は、一定の内径で軸線Ｏ方向の後端側に延びて締結部材１４０の後端面１４４に開口させられている。つまり、締結部材１４０には、この締結部材１４０を構成するテーパ部１４１及び円柱部１４２を軸線Ｏ方向に貫通する締結孔１４５が形成されているのである。
そして、締結孔１４５における後端側部分の内周面には、雌ねじ部１４６が形成されており、この雌ねじ部１４６は、軸線Ｏ方向での位置が、後端面１４４から円柱部１４２を越えてテーパ部１４１の後端にさしかかった位置までに亘って形成されている。
【００２０】
さらに、締結孔１４５が穿設されていることによって、略リング型状を呈している締結部材１４０の先端面１４３には、図４（ａ），（ｂ）に示すように、周方向で略等間隔に位置するように、軸線Ｏ方向の後端側に向かって軸線Ｏ方向に沿って切り込まれた複数（例えば３つ）のスリット１４７…が形成されており、締結部材１４０のテーパ部１４１の先端側部分が周方向で複数（例えば３つ）に分割されている。
これらスリット１４７…は、軸線Ｏ方向での位置が、先端面１４３からテーパ部１４１を越えずに円柱部１４２に至る手前の位置までに亘って形成されており、スリット１４７…の底部１４７Ａ…、すなわち、スリット１４７…における軸線Ｏ方向で最も後端側に位置する部分は、円弧状に形成されている。
【００２１】
また、締結孔１４５が開口させられていることによって、同じく略リング型状を呈している締結部材１４０の後端面１４４には、図４（ａ），（ｃ）に示すように、軸線Ｏ方向の先端側に凹む少なくとも一つ（例えば３つ）の凹部１４８…が、上述した固定ボルト１２０の先端面１２３に形成された凸部１２４…に対応した形状となるように、周方向で略等間隔に形成されている。
【００２２】
上記のような構成をなす刃部１３０が工具本体１１０に装着されている状態においては、工具本体１１０の取付孔１１２内に締結部材１４０が収容されていて、締結部材１４０におけるテーパ部１４１が取付孔１１２におけるテーパ孔１１３内に収容され、かつ、締結部材１４０における円柱部１４２が取付孔１１２における収納孔１１４内に収容された状態となっている。
【００２３】
また、締結部材１４０の後端面１４４に形成された凹部１４８…に対して、取付孔１１２の後端側からねじ込まれた固定ボルト１２０の先端面１２３に形成された凸部１２４…が嵌合させられている。
【００２４】
同じく、刃部１３０が工具本体１１０に装着されている状態においては、刃部１３０の後端側部分１３２が、取付孔１１２内に収容された締結部材１４０の締結孔１４５に挿入されるとともに、刃部１３０の後端側部分１３２に形成された雄ねじ部１３３が、締結部材１４０の締結孔１４５に形成された雌ねじ部１４６にねじ込まれている。
【００２５】
ここで、刃部１３０の切削部１３１における軸線Ｏ方向の後端側を向く壁面１３１Ｄが、工具本体１１０の先端面１１１と対向するように配置されて互いに密着させられていることにより、刃部１３０と工具本体１１０との軸線Ｏ方向で互いに近づく方向への相対移動が阻止されたまま、締結部材１４０が工具本体１１０に対して軸線Ｏ方向の先端側に相対移動させられていて、締結部材１４０のテーパ部１４１の外周面が取付孔１１２のテーパ孔１１３の内周面で押圧されている。
【００２６】
そして、締結部材１４０のテーパ部１４１の外周面が取付孔１１２のテーパ孔１１３の内周面で押圧されていることで、スリット１４７…によって周方向で複数に割されたテーパ部１４１が弾性変形させられて締結孔１４５が収縮し、刃部１３０の後端側部分１３２が締め付けられて、この刃部１３０が工具本体１１０に対して着脱可能に装着されているのである。
【００２７】
刃部１３０を工具本体１１０に装着する工程としては、まず、取付孔１１２における工具本体１１０の後端面１１６への開口部から軸線Ｏ方向の先端側に向かって、締結部材１４０を所定量挿入しておき、次いで、固定ボルト１２０を、その先端面１２３に形成された凸部１２４…と締結部材１４０の後端面１４４に形成された凹部１４８…とを互いに嵌合させながら、締結部材１４０を押し込みつつ挿入していく。
【００２８】
そのまま、固定ボルト１２０を挿入して、この固定ボルト１２０の雄ねじ部１２１を取付孔１１２の雌ねじ部１１５にねじ込んでいくことにより、締結部材１４０のテーパ部１４１が取付孔１１２におけるテーパ孔１１３内に収容されるとともに、このテーパ部１４１の外周面とテーパ孔１１３の内周面とが互いに対向して配置されて互いに当接した状態とする。
【００２９】
その後、取付孔１１２における工具本体１１０の先端面１１１への開口部から軸線Ｏ方向の後端側に向かって、刃部１３０の後端側部分１３２を挿入することにより、この刃部１３０の後端側部分１３２を取付孔１１２内に収容された締結部材１４０の締結孔１４５内に挿入していく。
そして、刃部１３０の後端側部分１３２に形成された雄ねじ部１３３を、締結部材１４０の締結孔１４５に形成された雌ねじ部１４６にねじ込んでいくことで、刃部１３０の切削部１３１における軸線Ｏ方向の後端側を向く壁面１３１Ｄが工具本体１１０の先端面１１１に当接して互いに係止した状態とする。
【００３０】
なお、この刃部１３０の後端側部分１３２の雄ねじ部１３３を締結孔１４５の雌ねじ部１４６にねじ込んでいくときには、例えば、刃部１３０の切削部１３１に形成された互いに平行な一対の平坦面１３１Ｃ，１３１Ｃにスパナをかけることによって、刃部１３０の後端側部分１３２の雄ねじ部１３３をねじ込んでいく。
【００３１】
刃部１３０の切削部１３１における軸線Ｏ方向の後端側を向く壁面１３１Ｄと工具本体１１０の先端面１１１とが当接した状態となると、刃部１３０と工具本体１１０との軸線Ｏ方向で互いに近づく方向への相対移動が阻止されるので、このまま、刃部１３０の後端側部分１３２の雄ねじ部１３３のねじ込みを継続していくと、締結部材１４０のみが、工具本体１１０に対して軸線Ｏ方向の先端側へ相対移動させられていく。
【００３２】
すると、締結部材１４０におけるテーパ部１４１の外周面が、取付孔１１２のテーパ孔１１３の内周面で押圧され、スリット１４７…によって周方向で複数に分割されたテーパ部１４１の先端側部分が、その内部に位置する締結孔１４５の内径を収縮していくように弾性変形させられる。
これにより、刃部１３０の後端側部分１３２が締結部材１４０の締結孔１４５によって締め付けられ、刃部１３０が工具本体１１０に対して着脱可能に装着されて固定される。
【００３３】
一方、刃部１３０を工具本体１１０から取り外す工程としては、刃部１３０の切削部１３１における軸線Ｏ方向の後端側を向く壁面１３１Ｄと工具本体１１０の先端面１１１との当接した状態を維持したまま、締結孔１４５の雌ねじ部１４６にねじ込まれた刃部１３０の後端側部分１３２の雄ねじ部１３３を緩めていくと、締結部材１４０が工具本体１１０に対して軸線Ｏ方向の後端側へ相対移動させられ、取付孔１１２のテーパ孔１１３の内周面による締結部材１４０のテーパ部１４１の外周面の押圧が解除される。
【００３４】
すると、取付孔１１２のテーパ孔１１３の内周面によって押圧されて、締結孔１４５の内径が収縮するように弾性変形させられていた締結部材１４０のテーパ部１４１における先端側部分が、自身の復元力によって押圧される前の状態まで戻り、締結孔１４５による刃部１３０の後端側部分１３２の締め付けが解除されるので、刃部１３０の後端側部分１３２を締結孔１４５から軸線Ｏ方向の先端側へ向かって抜き出すことができる。
【００３５】
このような構成とされた刃部交換式切削工具１００においては、工具本体１１０の後端側部分が工作機械の回転軸に取り付けられて、軸線Ｏ回りに回転させられることにより、刃部１３０の切削部１３１の外周切刃１３１Ａ，１３１Ａ及び先端切刃１３１Ｂ，１３１Ｂによってワークの切削加工が行われる。
【００３６】
本実施形態による刃部交換式切削工具１００によれば、取付孔１１２のテーパ孔１１３及び締結部材１４０のテーパ部１４１が軸線Ｏ方向の後端側に向かうにしたがい漸次拡径しているために、締結部材１４０を工具本体１１０に対して軸線Ｏ方向の先端側に相対移動させたときに、スリット１４７…の存在によって収縮可能となっている締結孔１４５が収縮して、この締結孔１４５内に挿入された刃部１３０の後端側部分１３２を強固に締め付けることができる。
【００３７】
そして、締結部材１４０に形成されたスリット１４７…は、締結部材１４０の先端面１４３から後端側に向かって切り込まれているので、テーパ部１４１における先端側部分の方が弾性変形しやすくなっている、すなわち、締結孔１４５における先端側部分が収縮しやすくなっているため、とくに、締結孔１４５に挿入された刃部１３０の後端側部分１３２における先端側寄りの部分を締め付けることとなる。
【００３８】
つまり、ワークの切削に供される切削部１３１により近い、刃部１３０の後端側部分１３２における先端側寄りの部分が強固に締め付けられるので、切削抵抗によっても決して刃部１３０が緩むことなく、刃部１３０の装着状態を安定して維持することができるのである。
【００３９】
このとき、取付孔１１２のテーパ孔１１３及び締結部材１４０のテーパ部１４１における片角でのテーパ角度θが、２〜２５゜の範囲に設定されていることによって、これらテーパ孔１１３の内周面とテーパ部１４１の外周面との間に適度な押圧力を生じさせることができている。
【００４０】
このテーパ角度θが２゜より小さくなると、テーパ孔１１３の内周面とテーパ部１４１の外周面との間で生じる押圧力が（くさび効果によって）高くなりすぎ、締結部材１４０を工具本体１１０に対して軸線Ｏ方向の後端側へ相対移動させることができなくなって、刃部１３０が工具本体１１０から外れなくなってしまうおそれがある。逆に、テーパ角度θが２５゜より大きくなっても、押圧力が小さくなり十分な刃部１３０の締め付けができなくなるおそれがある。
【００４１】
また、刃部１３０の後端側部分１３２に形成された雄ねじ部１３３を、締結部材１４０の締結孔１４５に形成された雌ねじ部１４６にねじ込むことによって、この締結部材１４０を工具本体１１０に対して軸線Ｏ方向の先端側に相対移動させる構成を採用していることから、従来のようなキャップを用いなくても、刃部１３０を工具本体１１０へ容易に装着することができる。
【００４２】
同じく、刃部１３０の後端側部分１３２の雄ねじ部１３３を、締結孔１４５の雌ねじ部１４６にねじ込む構成を採用していることで、締結孔１４５の収縮による刃部１３０の後端側部分１３２の締め付けに加えて、ねじ同士の螺合によっても、刃部１３０を固定することができるので、刃部１３０の装着状態をより安定化させることができる。
【００４３】
そして、本実施形態のように、工具本体１１０の先端側部分が、軸線Ｏ方向の先端側に向かうにしたがい外径が一定の勾配で漸次縮径していくようなテーパ面１１０Ａを有するような先細り形状になっていたとしても、取付孔１１２におけるテーパ孔１１３が軸線Ｏ方向の先端側に向かうにしたがい内径が漸次縮径しているので、工具本体１１０における先端面１１１付近でも、さほど肉薄となることがない。
これにより、工具本体１１０の剛性を不用意に低めることなく、工具本体１１０の先端側部分をより小径化させることができ、様々なワークの切削に対応できる。
【００４６】
また、上記の実施形態において、工具本体１１０の後端面１１６から軸線Ｏ方向の先端側に向かって、工具本体１１０、固定ボルト１２０、刃部１３０を貫通するようにして、内部給油穴が形成されていても構わない。
【００４７】
【発明の効果】
本発明によれば、取付孔のテーパ孔及び締結部材のテーパ部が軸線方向の後端側に向かうにしたがい漸次拡径しているため、締結部材が工具本体に対して軸線方向の先端側に相対移動させられることにより、締結部材の締結孔が収縮して刃部の後端側部分を強固に締め付けることができる。
そして、取付孔のテーパ孔が、軸線方向の後端側に向かうにしたがい漸次拡径させられていることにより、たとえ、工具本体の先端側部分を軸線方向の先端側に向かうにしたがい縮径するような先細り形状にしたとしても、必要以上に肉薄となることがないので、工具本体の剛性を低めてしまうことなく、先端側部分をより小径化した工具本体を製作できて、様々なワークの切削に対応できる。
【図面の簡単な説明】
【図１】本発明の実施形態による刃部交換式切削工具を示す一部破断側面図である。
【図２】本発明の実施形態による刃部交換式切削工具を示す一部破断側面図である。
【図３】本発明の実施形態による刃部交換式切削工具の刃部を示す側面図である。
【図４】（ａ）は本発明の実施形態による刃部交換式切削工具の締結部材を示す側面図、（ｂ）は同締結部材の先端面図、（ｃ）は同締結部材の後端面図である。
【図５】（ａ）は従来の刃部交換式切削工具の一例を示す一部破断側面図、（ｂ）は同刃部交換式切削工具の締結部材を示す一部破断側面図である。
【符号の説明】
１００刃部交換式切削工具
１１０工具本体
１１２取付孔
１１３テーパ孔
１２０固定ボルト（固定部材）
１２４凸部
１３０刃部
１３２後端側部分
１３３雄ねじ部
１４０締結部材
１４１テーパ部
１４３先端面
１４５締結孔
１４６雌ねじ部
１４７スリット
１４８凹部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blade part exchangeable cutting tool in which a blade part is detachably attached to a tool body.
[0002]
[Prior art]
Conventionally, as an example of this kind of blade part exchangeable cutting tool, there is a blade part exchangeable cutting tool 10 as shown in FIG. 5, for example, with respect to the tool body 11 rotated around the axis O. A blade portion (not shown) is detachably mounted and fixed.
The tool body 11 has a mounting hole 12 drilled from the front end surface 11A toward the rear end side, and the mounting hole 12 has an inner diameter as it goes to the rear end side (left side in the figure) in the axis O direction. A tapered hole 13 having a substantially frustoconical hole shape that gradually decreases in diameter is provided.
[0003]
And the fastening member 20 which has the substantially frustoconical taper part 21 in which an outer diameter reduces gradually as it goes to the rear-end side of the axis line O direction is accommodated in the attachment hole 12, and this fastening member 20 contains. The fastening hole 22 is formed from the front end surface 20A toward the rear end side in the axis O direction, the rear end side in the axis O direction from the front end surface 20A, and the front end side in the axis O direction from the rear end surface 20B. A plurality of slits 23 are cut toward the top.
In addition, a substantially cylindrical cap 30 is attached to the tip portion of the tool body 11 so that the fastening member 20 accommodated in the mounting hole 12 does not fall off. A female screw portion 31 of the cap 30 is screwed into a male screw portion 14 formed on the outer peripheral surface.
[0004]
When the blade portion is mounted on the tool body 11, the cap 30 is screwed after the rear end portion of the blade portion is inserted into the fastening hole 22 of the fastening member 20 accommodated in the mounting hole 12. The fastening member 20 is pressed by the cap 30, and the fastening member 20 is moved relative to the tool body 11 toward the rear end side in the axis O direction.
Then, the outer peripheral surface of the taper portion 21 of the fastening member 20 is pressed by the inner peripheral surface of the taper hole 13 of the mounting hole 12, the fastening hole 22 contracts, and the rear end side portion of the blade portion is tightened. Is detachably attached to the tool body 11.
[0005]
[Problems to be solved by the invention]
However, in the blade part exchange-type cutting tool 10 as described above, the tapered hole 13 of the mounting hole 12 is gradually reduced in diameter toward the rear end side in the axis O direction. If the tip end portion is tapered so that the outer diameter gradually decreases as it goes toward the tip end in the direction of the axis O, the tool body 11 inevitably becomes thinner as it goes toward the tip end in the direction of the axis O. As a result, the tip end portion of the tool body 11 could not be reduced in diameter.
[0006]
This invention is made | formed in view of the said subject, and it aims at providing the blade part exchange type cutting tool which can make a tool main body into a tapered shape, without reducing the rigidity.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve such an object, the blade part replaceable cutting tool according to the present invention includes a blade part having a cutting part including at least one cutting edge, A blade-exchangeable cutting tool that is inserted into a mounting hole formed in the tool body and in which the blade part is detachably mounted. The mounting hole is formed on the rear end side in the axial direction of the tool body. A substantially truncated cone having a substantially truncated cone hole-shaped tapered hole whose inner diameter gradually increases as it goes in the direction, and an outer diameter gradually increases as it goes toward the rear end side in the axial direction in the mounting hole. A fastening member having a tapered portion is accommodated, and a fastening hole is formed in the fastening member from the front end surface toward the rear end side in the axial direction, and from the front end surface in the axial direction. have been cut slit toward the rear end, the rear end of the cutting portion The part has a male thread part, the fastening hole has a female thread part, and the fastening member is moved into the female thread part by screwing the male thread part of the rear end side portion of the blade part into the female thread part of the fastening hole. The blade is moved relative to the front end side in the axial direction with respect to the main body, the outer peripheral surface of the taper portion of the fastening member is pressed by the inner peripheral surface of the taper hole of the mounting hole, and the fastening hole contracts and the blade The blade is attached detachably by tightening a rear end side portion of the part.
In the blade part replaceable cutting tool of the present invention having such a configuration, the taper hole of the mounting hole and the taper part of the fastening member gradually increase in diameter toward the rear end side in the axial direction. Is moved relative to the tool body in the axial direction, the fastening hole of the fastening member contracts, and the rear end portion of the blade portion can be firmly tightened.
Moreover, the taper hole of the mounting hole is gradually increased in diameter as it goes toward the rear end side in the axial direction, so that the diameter of the tip side portion of the tool body decreases as it goes toward the front end side in the axial direction. Even if such a tapered shape is used, the thickness of the tool body is not reduced more than necessary, and the rigidity of the tool body is not lowered.
[0008]
The rear end portion of the blade portion has a male screw portion, the fastening hole has a female screw portion, and the male screw portion of the rear end portion of the blade portion is screwed into the female screw portion of the fastening hole. As a result, the fastening member is moved relative to the tool body relative to the tip end side in the axial direction, so that the male screw portion formed on the rear end portion of the blade portion is screwed into the female screw portion of the fastening hole. Only by this, the rear end portion of the blade portion can be easily fastened.
Furthermore, in addition to being able to fasten the rear end side portion of the blade portion by the fastening hole of the fastening member, the blade portion can be fastened by screwing the screws together, so that the blade portion can be tightened more firmly. It is possible to stabilize the mounting state of the blade portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIGS. 1 and 2 are partially cutaway side views showing a blade part replaceable cutting tool according to an embodiment of the present invention, FIG. 3 is a side view showing the blade part of the blade part replaceable cutting tool, and FIG. The side view which shows the fastening member of the blade part exchange-type cutting tool, (b) is the front end view of the fastening member, (c) is the rear end view of the fastening member.
[0011]
As shown in FIGS. 1 and 2, the blade part replaceable cutting tool 100 according to the first embodiment is fixed to a tool main body 110 that is rotated around an axis O and is detachably attached to the tool main body 110. And the fastening member 140 used to fasten the blade part 130 and attach it to the tool body 110.
[0012]
As shown in FIGS. 1 and 2, the tool body 110 is made of, for example, steel and is formed in a substantially cylindrical shape with the axis O as the center, and the rear end side in the direction of the axis O (see FIG. A mounting hole 112 is formed around the axis O toward the middle right).
In addition, the tip side portion of the tool body 110 has a tapered surface 110A whose outer diameter gradually decreases with a constant gradient toward the tip side in the axis O direction (left side in the figure). It has a tapered shape.
[0013]
The mounting hole 112 is open to the front end surface 111 of the tool body 110 and has a tapered hole 113 having a substantially frustoconical hole shape in which the inner diameter gradually increases with a constant gradient toward the rear end side in the axis O direction. A storage hole 114 that is smoothly connected to the rear end side of the taper hole 113 and has a constant inner diameter and extending toward the rear end side in the axis O direction, and a storage hole 114 connected to the rear end side of the storage hole 114 and a tool. The main body 110 includes a female thread portion 115 that opens to the rear end surface 116 of the main body 110.
The taper holes 113 of the mounting hole 112 have a taper angle θ at one angle of 2 to 25 °.
[0014]
Then, a male screw portion 121 located at the rear end side portion of the fixing bolt 120 (fixing member) having a substantially columnar shape is screwed toward the tip end side in the axis O direction with respect to the female screw portion 115 of the mounting hole 112. In addition, the front end portion 122 of the fixing bolt 120 is accommodated in the accommodation hole 114 of the attachment hole 112.
Moreover, at least one (for example, three) convex portions 124 projecting toward the tip end side in the axis O direction are provided at substantially equal intervals in the circumferential direction on the radially outer side portion of the tip face 123 of the fixing bolt 120. On the other hand, a hexagonal hole 126 is formed in the rear end surface 125 of the fixing bolt 120.
[0015]
As shown in FIG. 3, the blade portion 130 is made of, for example, a cemented carbide, and is connected to a cutting portion 131 in which at least one cutting edge is formed at the forefront, and a rear end side of the cutting portion 131 via a stepped portion. It is composed of a substantially cylindrical rear end side portion 132 and is formed around the axis O.
In addition, a male threaded portion 133 is formed on the outer peripheral surface of the rear end portion of the rear end portion 132 of the blade portion 130.
[0016]
Here, the cutting part 131 of the blade part 130 will be described in detail. The cutting part 131 of the blade part 130 is located opposite to each other with respect to the axis O, and twists toward the rear side in the tool rotation direction T toward the rear end side in the axis O direction. A pair of chip discharge grooves are formed, and outer peripheral cutting edges 131A and 131A are formed on the outer peripheral side ridge lines in these chip discharge grooves.
In addition, the tip side portion of the wall surface facing the front side in the tool rotation direction T in the pair of chip discharge grooves is a rake face, and the cutting edge of the blade part 130 is formed at the intersection ridge line portion of the rake face and the tip flank face. And a pair of leading edge cutting blades 131B and 131B extending from the vicinity of the axis O toward the outer peripheral side on the opposite sides of the axis O.
[0017]
Furthermore, in this cutting part 131, the part on the rear end side with respect to the part where the pair of outer peripheral cutting edges 131A, 131A is formed is substantially disc-shaped, and the outer peripheral surface is notched so that the axis line A pair of flat surfaces 131C and 131C are formed so as to be opposite to each other with respect to O and parallel to each other.
Here, since the rear end side portion 132 is connected to the rear end side of the cutting portion 131 through a stepped portion, the cutting portion 131 stands upright from the outer peripheral surface of the rear end side portion 132 and is formed on the cutting portion 131. A wall surface 131 </ b> D that faces the rear end side in the axis O direction so as to intersect the outer peripheral surface is formed.
[0018]
As shown in FIG. 4, the fastening member 140 includes a tapered portion 141 having a substantially truncated cone shape whose outer diameter gradually increases with a constant gradient toward the rear end side in the axis O direction, and the tapered portion. 141 is formed of a cylindrical portion 142 that is smoothly connected to the rear end side of 141 and has a constant outer diameter and extends toward the rear end side in the direction of the axis O, and is formed around the axis O.
The taper part 141 of the fastening member 140 has a taper angle θ at one angle set to the same value (2 to 25 °) as the taper angle θ of the taper holes 113 of the mounting hole 112.
[0019]
The fastening member 140 has a fastening hole 145 centered on the axis O from the front end surface 143 toward the rear end side in the axis O direction. The fastening hole 145 has a constant inner diameter. It extends to the rear end side in the direction of the axis O and is opened on the rear end surface 144 of the fastening member 140. That is, the fastening member 140 is formed with a fastening hole 145 that penetrates the taper portion 141 and the cylindrical portion 142 constituting the fastening member 140 in the axis O direction.
An internal thread portion 146 is formed on the inner peripheral surface of the rear end side portion of the fastening hole 145, and the internal thread portion 146 has a position in the axis O direction beyond the cylindrical portion 142 from the rear end surface 144. It is formed over a position approaching the rear end of the tapered portion 141.
[0020]
Furthermore, as shown in FIGS. 4A and 4B, the fastening surface 140 of the fastening member 140 having a substantially ring shape is formed substantially in the circumferential direction because the fastening hole 145 is formed. A plurality of (for example, three) slits 147 that are cut along the axis O direction toward the rear end side in the axis O direction are formed so as to be positioned at equal intervals, and the tapered portion of the fastening member 140 is formed. The front end side portion of 141 is divided into a plurality (for example, three) in the circumferential direction.
These slits 147... Are formed so that the position in the direction of the axis O extends from the front end surface 143 to a position just before reaching the cylindrical portion 142 without passing through the tapered portion 141, and the bottom portion 147 A of the slit 147. That is, the portion of the slits 147... That is located closest to the rear end side in the axis O direction is formed in an arc shape.
[0021]
In addition, since the fastening hole 145 is opened, the rear end surface 144 of the fastening member 140 having a substantially ring shape is formed in the direction of the axis O as shown in FIGS. Are substantially equal in the circumferential direction so that at least one (for example, three) recesses 148... That are recessed toward the tip end of the screw have a shape corresponding to the protrusions 124 formed on the tip surface 123 of the fixing bolt 120 described above. It is formed at intervals.
[0022]
In a state where the blade portion 130 having the above-described configuration is mounted on the tool body 110, the fastening member 140 is accommodated in the mounting hole 112 of the tool body 110, and the taper portion 141 of the fastening member 140 is attached. The cylindrical portion 142 of the fastening member 140 is accommodated in the tapered hole 113 of the hole 112 and is accommodated in the storage hole 114 of the mounting hole 112.
[0023]
Further, the convex portions 124 formed on the front end surface 123 of the fixing bolt 120 screwed from the rear end side of the mounting hole 112 are fitted into the concave portions 148 formed on the rear end surface 144 of the fastening member 140. It has been.
[0024]
Similarly, in a state where the blade portion 130 is mounted on the tool body 110, the rear end side portion 132 of the blade portion 130 is inserted into the fastening hole 145 of the fastening member 140 accommodated in the mounting hole 112, and A male screw part 133 formed in the rear end side portion 132 of the blade part 130 is screwed into a female screw part 146 formed in the fastening hole 145 of the fastening member 140.
[0025]
Here, the wall portion 131D facing the rear end side in the axis O direction in the cutting portion 131 of the blade portion 130 is disposed so as to face the front end surface 111 of the tool body 110 and is brought into close contact with each other. The fastening member 140 is moved relatively to the tip end side in the axis O direction with respect to the tool body 110 while the relative movement of the tool 130 and the tool body 110 in the direction of approaching each other in the direction of the axis O is prevented. The outer peripheral surface of the 140 tapered portion 141 is pressed by the inner peripheral surface of the tapered hole 113 of the mounting hole 112.
[0026]
The outer peripheral surface of the taper portion 141 of the fastening member 140 is pressed by the inner peripheral surface of the taper hole 113 of the mounting hole 112, so that the taper portion 141 divided into a plurality in the circumferential direction by the slits 147. As a result, the fastening hole 145 contracts, the rear end side portion 132 of the blade part 130 is tightened, and the blade part 130 is detachably attached to the tool body 110.
[0027]
As a process of attaching the blade part 130 to the tool main body 110, first, a predetermined amount of the fastening member 140 is inserted from the opening to the rear end surface 116 of the tool main body 110 in the attachment hole 112 toward the front end side in the axis O direction. Then, the fixing bolt 120 is pushed into the fastening member 140 while fitting the convex portions 124 formed on the front end surface 123 thereof with the concave portions 148 formed on the rear end surface 144 of the fastening member 140. While inserting.
[0028]
The fixing bolt 120 is inserted as it is, and the male screw portion 121 of the fixing bolt 120 is screwed into the female screw portion 115 of the mounting hole 112, whereby the taper portion 141 of the fastening member 140 is inserted into the taper hole 113 in the mounting hole 112. While being accommodated, the outer peripheral surface of this taper part 141 and the inner peripheral surface of the taper hole 113 are arranged facing each other and are in contact with each other.
[0029]
Thereafter, by inserting the rear end side portion 132 of the blade portion 130 toward the rear end side in the axis O direction from the opening portion of the tool body 110 in the mounting hole 112 toward the rear end side in the axis O direction, The end portion 132 is inserted into the fastening hole 145 of the fastening member 140 accommodated in the mounting hole 112.
Then, the male screw part 133 formed in the rear end side portion 132 of the blade part 130 is screwed into the female screw part 146 formed in the fastening hole 145 of the fastening member 140, whereby the axis line in the cutting part 131 of the blade part 130. The wall surface 131 </ b> D facing the rear end side in the O direction is in contact with the front end surface 111 of the tool main body 110 and locked to each other.
[0030]
When the male threaded portion 133 of the rear end portion 132 of the blade portion 130 is screwed into the female threaded portion 146 of the fastening hole 145, for example, a pair of parallel flat surfaces formed on the cutting portion 131 of the blade portion 130, for example. By applying a spanner to 131C and 131C, the male threaded portion 133 of the rear end side portion 132 of the blade portion 130 is screwed.
[0031]
When the wall surface 131D facing the rear end side in the axis O direction in the cutting portion 131 of the blade portion 130 and the tip surface 111 of the tool main body 110 are in contact with each other, the blade portion 130 and the tool main body 110 are mutually in the axis O direction. Since the relative movement in the approaching direction is prevented, if the screwing of the male threaded portion 133 of the rear end side portion 132 of the blade portion 130 is continued as it is, only the fastening member 140 has the axis O with respect to the tool body 110. It is moved relative to the tip of the direction.
[0032]
Then, the outer peripheral surface of the taper portion 141 in the fastening member 140 is pressed by the inner peripheral surface of the taper hole 113 of the mounting hole 112, and the tip side portion of the taper portion 141 divided into a plurality in the circumferential direction by the slits 147. It is elastically deformed so that the inner diameter of the fastening hole 145 located inside thereof is contracted.
Thereby, the rear end side portion 132 of the blade portion 130 is fastened by the fastening hole 145 of the fastening member 140, and the blade portion 130 is detachably attached to the tool body 110 and fixed.
[0033]
On the other hand, as the step of removing the blade portion 130 from the tool body 110, the state in which the wall surface 131D facing the rear end side in the axis O direction in the cutting portion 131 of the blade portion 130 and the tip surface 111 of the tool body 110 is kept in contact. If the male threaded portion 133 of the rear end portion 132 of the blade portion 130 screwed into the female threaded portion 146 of the fastening hole 145 is loosened while the fastening member 140 is loosened with respect to the tool body 110 in the axis O direction. And the pressing of the outer peripheral surface of the tapered portion 141 of the fastening member 140 by the inner peripheral surface of the tapered hole 113 of the mounting hole 112 is released.
[0034]
Then, the front end side portion of the taper portion 141 of the fastening member 140 that is pressed by the inner peripheral surface of the taper hole 113 of the mounting hole 112 and elastically deformed so that the inner diameter of the fastening hole 145 contracts is restored. Returning to the state before being pressed by the force, the fastening of the rear end side portion 132 of the blade portion 130 by the fastening hole 145 is released, so the rear end side portion 132 of the blade portion 130 is moved from the fastening hole 145 in the axis O direction. It can be extracted toward the tip side.
[0035]
In the blade part exchangeable cutting tool 100 having such a configuration, the rear end side portion of the tool body 110 is attached to the rotating shaft of the machine tool and rotated about the axis O, whereby the blade part 130 The workpiece is cut by the outer peripheral cutting edges 131A and 131A and the tip cutting edges 131B and 131B of the cutting part 131.
[0036]
According to the blade part exchangeable cutting tool 100 according to the present embodiment, the tapered hole 113 of the mounting hole 112 and the tapered part 141 of the fastening member 140 are gradually enlarged in diameter toward the rear end side in the axis O direction. When the fastening member 140 is moved relative to the tool body 110 in the direction of the axis O, the fastening hole 145 that can be shrunk due to the presence of the slits 147. The rear end side portion 132 of the blade portion 130 inserted into can be firmly tightened.
[0037]
Since the slits 147... Formed in the fastening member 140 are cut from the front end surface 143 of the fastening member 140 toward the rear end side, the front end side portion of the tapered portion 141 is more easily elastically deformed. That is, since the front end side portion in the fastening hole 145 is easily contracted, the portion closer to the front end side in the rear end side portion 132 of the blade portion 130 inserted into the fastening hole 145 is particularly tightened. .
[0038]
That is, since the portion closer to the front end side in the rear end side portion 132 of the blade portion 130 that is closer to the cutting portion 131 used for cutting the workpiece is firmly tightened, the blade portion 130 never loosens even by cutting resistance, The mounting state of the blade part 130 can be stably maintained.
[0039]
At this time, the taper angle θ at one angle of the taper hole 113 of the attachment hole 112 and the taper portion 141 of the fastening member 140 is set in the range of 2 to 25 °, so that the inner peripheral surfaces of these taper holes 113 are obtained. And an appropriate pressing force can be generated between the outer peripheral surface of the tapered portion 141 and the outer peripheral surface of the tapered portion 141.
[0040]
When the taper angle θ is smaller than 2 °, the pressing force generated between the inner peripheral surface of the tapered hole 113 and the outer peripheral surface of the tapered portion 141 becomes too high (due to the wedge effect), and the fastening member 140 is attached to the tool main body 110. On the other hand, there is a possibility that the blade portion 130 cannot be detached from the tool body 110 because it cannot be relatively moved to the rear end side in the direction of the axis O. On the other hand, even if the taper angle θ is larger than 25 °, the pressing force is reduced, and there is a possibility that the blade part 130 cannot be sufficiently tightened.
[0041]
Further, by screwing the male screw portion 133 formed on the rear end side portion 132 of the blade portion 130 into the female screw portion 146 formed in the fastening hole 145 of the fastening member 140, the fastening member 140 is attached to the tool main body 110. Since the configuration of relative movement to the tip side in the direction of the axis O is employed, the blade portion 130 can be easily attached to the tool body 110 without using a conventional cap.
[0042]
Similarly, by adopting a configuration in which the male screw portion 133 of the rear end side portion 132 of the blade portion 130 is screwed into the female screw portion 146 of the fastening hole 145, the rear end side portion 132 of the blade portion 130 due to contraction of the fastening hole 145 is adopted. In addition to tightening, the blade portion 130 can be fixed by screwing the screws together, so that the mounting state of the blade portion 130 can be further stabilized.
[0043]
Then, as in the present embodiment, the tip side portion of the tool body 110 has a tapered surface 110A whose outer diameter is gradually reduced with a constant gradient toward the tip side in the direction of the axis O. Even if the taper hole 113 is tapered, the inner diameter gradually decreases as the tapered hole 113 in the mounting hole 112 moves toward the front end side in the axis O direction. Never become.
As a result, the tip end portion of the tool main body 110 can be made smaller in diameter without inadvertently reducing the rigidity of the tool main body 110, and can cope with cutting of various workpieces.
[0046]
Further, in the above-described embodiment, an internal oil supply hole is formed so as to penetrate the tool body 110, the fixing bolt 120, and the blade portion 130 from the rear end surface 116 of the tool body 110 toward the front end side in the axis O direction. It does not matter.
[0047]
【The invention's effect】
According to the present invention, since the taper hole of the attachment hole and the taper portion of the fastening member gradually increase in diameter toward the rear end side in the axial direction, the fastening member is located on the front end side in the axial direction with respect to the tool body. By being relatively moved, the fastening hole of the fastening member contracts and the rear end side portion of the blade portion can be firmly fastened.
The taper hole of the mounting hole is gradually enlarged in diameter toward the rear end side in the axial direction, so that the diameter of the tip side portion of the tool body is reduced in the direction toward the front end side in the axial direction. Even with such a tapered shape, it will not be thinner than necessary, so the tool body with a smaller diameter on the tip side can be manufactured without reducing the rigidity of the tool body, and various workpieces can be manufactured. Can handle cutting.
[Brief description of the drawings]
FIG. 1 is a partially cutaway side view showing a blade replacement type cutting tool according to an embodiment of the present invention.
FIG. 2 is a partially cutaway side view showing a blade exchange type cutting tool according to an embodiment of the present invention.
FIG. 3 is a side view showing a blade portion of the blade portion replaceable cutting tool according to the embodiment of the present invention.
FIG. 4A is a side view showing a fastening member of a blade replacement type cutting tool according to an embodiment of the present invention, FIG. 4B is a front end view of the fastening member, and FIG. 4C is a rear end face of the fastening member. FIG.
FIG. 5A is a partially cutaway side view showing an example of a conventional blade exchangeable cutting tool, and FIG. 5B is a partially cutaway side view showing a fastening member of the blade exchangeable cutting tool.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Blade part exchange-type cutting tool 110 Tool main body 112 Mounting hole 113 Tapered hole 120 Fixing bolt (fixing member)
124 Convex part 130 Blade part 132 Rear end side part 133 Male thread part 140 Fastening member 141 Tapered part 143 Tip surface 145 Fastening hole 146 Female thread part 147 Slit 148 Recessed part

Claims

A blade-replaceable cutting method in which a rear end side portion of a blade portion having a cutting portion provided with at least one cutting blade is inserted into a mounting hole formed in the tool body, and the blade portion is detachably mounted. A tool,
The attachment hole has a tapered hole having a substantially frustoconical hole shape whose inner diameter gradually increases as it goes toward the rear end side in the axial direction of the tool body, and the rear end in the axial direction is included in the attachment hole. A fastening member having a substantially frustoconical taper portion in which the outer diameter gradually expands toward the end side is accommodated,
The fastening member is provided with a fastening hole from the front end surface toward the rear end side in the axial direction, and a slit is cut from the front end surface toward the rear end side in the axial direction. And
The rear end portion of the blade portion has a male screw portion,
The fastening hole has a female screw part,
When the male screw portion of the rear end side portion of the blade portion is screwed into the female screw portion of the fastening hole, the fastening member is moved relative to the tool body in the axial direction, and the fastening member The outer peripheral surface of the tapered portion is pressed by the inner peripheral surface of the tapered hole of the mounting hole, the fastening hole contracts, the rear end side portion of the blade portion is tightened, and the blade portion is detachably mounted. The blade part exchange-type cutting tool characterized by the above-mentioned.