| 摘要 |
PROBLEM TO BE SOLVED: To improve chip discharge performance in the axial direction of an unequal reed end mill.SOLUTION: The unequal reed end mill 1 comprises a blade part 5 composed of a tip cutting edge 2 and outer peripheral helical cutting edges 3 and 4 and a handle part 6, and comprises a width widening side discharge groove 7 for gradually increasing a width of a chip discharge groove between the outer peripheral cutting edges toward the handle part direction from the tip and a width narrowing side discharge groove 8 for gradually reducing toward the handle part direction from the tip, which are mutually different in torsion angles α and &bgr; of the adjacent outer peripheral cutting edges. The groove bottom depth 7d of the width widening side discharge groove is gradually reduced toward handle part cut-up parts 11 and 12 from the tip, and the groove bottom depth 8d of the width narrowing side discharge groove is gradually increased. A core thickness diameter 14a contacting with the groove bottom 8a of the width narrowing side discharge groove is set larger than a core thickness diameter 13a contacting with the groove bottom 7a of the width widening side discharge groove in the tip. The core thickness diameters 13b and 14b contacting with the groove bottoms of the width widening and width narrowing discharge grooves are set the same in a position for equally dividing the outer peripheral cutting edges in a cross section in the axial direction. |
