To pursue reamer finishing properties of a cutting edge part in the further rear end side out of the whole cutting edge, and to pursue cutting performance of the cutting edge part in the further tip end side in a drill having the cutting edge with a different tip end angle depending on the position.
A ridge line connecting the tip ends of the cutting edges of the drill comprises a part of an ellipse f1 and a straight line f2. A separation point H of an ellipse part from a straight line part is assumed to be (x0, y0). The straight line f2 is a tangent to the ellipse f1 in the separation point H. It is assumed that a1 is an area from the tip end of the drill to x0, a2 is an area from x0 to the origin, and a3 is a negative area, on the X-axis. The ridge line connecting the tip ends of the cutting edges is formed in a straight line along the tangent f2 in the area a1, and is formed along the reference ellipse f1 in the area a2. A margin is formed in the area a3 continuously from a flank of the cutting edge.
COPYRIGHT: (C)2010,JPO&INPIT
| WO/2017/037956 | HARD COATING AND HARD COATING-COVERED MEMBER |
HOSOI MASANORI
NAKAHATA TATSUO
TAKAHASHI HIDEJI
| JP2008105911A | 2008-05-08 | |||
| JPH02237708A | 1990-09-20 | |||
| JP2008036759A | 2008-02-21 | |||
| JPH02237708A | 1990-09-20 | |||
| JP2008105911A | 2008-05-08 |
| US1309706A | 1919-07-15 | |||
| US3443459A | 1969-05-13 | |||
| US4440532A | 1984-04-03 | |||
| US1309706A | 1919-07-15 | |||
| US3443459A | 1969-05-13 | |||
| US4440532A | 1984-04-03 |
Yoshio Arafune
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