END MILL

• Main Author: SHIBATA SHOHEI
• Format: Patent
• Language: English; Japanese
• Published: 14.04.2023
• Subjects: MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; MILLING; PERFORMING OPERATIONS; TRANSPORTING

To provide an end mill that can reduce surface roughness of a material to be ground subjected to processing and secure perpendicularity of a processed surface of the material, although the material is hard to ground such as a stainless steel.SOLUTION: An end mill 100 comprises a plurality of end cutting edges 1-4, a plurality of outer peripheral cutting edges 11-14 formed consecutively in a longitudinal direction, and a plurality of twisted grooves 21-24 arranged adjacently to the end cutting edges 1-4 and the outer peripheral cutting edges 11-14, where angles α1 and α2 formed by the plurality of end cutting edges 1-4 are different from each other, and twist angles β1 and β2 of the plurality of outer peripheral cutting edges 11-14 are different from each other. Lengths L0 which are lengths of the outer peripheral cutting edges 11-14 in the longitudinal direction are more than three times of outer diameters D1 thereof. Clearance angles θ1 of 0.1°-3.0°are formed in the outer peripheral cutting edges 11-14 with widths of 10-100 μm, and differences between the angles β1 and β2 which are different from each other of the plurality of outer peripheral cutting edges 11-14 are set to be in a range of 1°or more and 3°or less.SELECTED DRAWING: Figure 2 【課題】ステンレス鋼等の難削材に対しても、加工後における被削材の面粗さを小さくし、かつ加工面の垂直度を確保できるエンドミルを提供する。【解決手段】複数の底刃１～４当該底刃１～４と連続して長手方向に形成される複数の外周刃１１～１４当該底刃１～４および外周刃１１～１４に隣接配置される複数のねじれ溝２１～２４を有して、これら複数の底刃１～４が形成する中心の角度α１、α２が互いに異なり、かつ複数の外周刃１１～１４のねじれ角β１、β２が互いに異なるエンドミル１００において、長手方向における外周刃１１～１４の長さである刃長Ｌ０が外径Ｄ１の３倍以上であり、当該外周刃１１～１４に０．１°～３．０°の逃げ角θ１を１０～１００μｍの幅で設けて、複数の外周刃１１～１４の互いに異なるねじれ角β１、β２同士の差異は１°以上３°以下の範囲とする。【選択図】図２