| 摘要 |
PURPOSE:To make easy of discharge on cutting chip by forming cutting chip discharging channels in shallow and in nearly L letter shape in sectional form, and pressing a cutting chip on a flat plate part with a wall on rear side in rotational direction, while preventing the cutting chip from curing on making the cutting chip abut on a front side wall at a side end part. CONSTITUTION:A cutting chip discharging channel 3 is made to be in nearly L letter shape in cross sessional form, and an angle between a front side wall 31 in rotational direction and a rear side wall 32 is made in about 90 deg.. Together with formation of a projection 33 on the front side wall 31, a wall 35 is formed at a position retreated from the wall 31 on outer peripheral side than the projection. A generated cutting chip is pushed up as being pressed to the wall 32 at a flat plate part 40, and the same is moved into a portion widened on account of the wall 35 as being pressed to the wall 31 at a side part for being prevented from curling, thereby discharge is performed smoothly. |
