| 摘要 |
A drill point (1) for drilling sandwich panels (100), composite materials and similar, comprising a shank (2) for coupling into the chuck a tool apt to drive said point (1) in rotation; a drilling member, integral to the shank, comprising a substantially cylindrical working portion (3), and a cutting head (4), located at the end of the working portion (3), having cutting edges (C); wherein onto the surface of the working portion (3) there are obtained helical flutes (5), spirally arranged about a substantially central longitudinal axis (A-A) of the working portion (3), the flutes (5) ending on a top face (4') of the cutting head (4), characterized in that the constructive geometry thereof provides a helix angle (e) with respect to the longitudinal axis (A-A), along which there develop the helical flutes (5), substantially comprised in a range of 30° to 35°; a chisel edge angle (?) substantially comprised in a range of 1° to 5°; a first radial relief angle (?r) substantially of 7°; a second external relief angle (a) substantially comprised in a range of 22° to 26°; an inferior relief angle (d) of the helical flutes (5) on the cutting head (4) with respect to the longitudinal axis (A-A) substantially of about 25°; a section of the cutting head (4), commonly known as face (6), for raising and letting flow a chip deriving from the drilling action, having length (L6) substantially comprised in a range of 0.3 to 0.5 mm; an angle (?) included between the face (6) and the relief (7) of the flutes (5) on the head (4) substantially comprised in a range of 70° to 80°; a central core (8) of the point (1) with diameter (D8) substantially comprised in a range of 1.5 to 2.7 mm; a sharpening angle (ß) of the head (4) of the point (1) substantially comprised in a range of 110° to 150°; so as to carry out a one-shot drilling of sandwich panels (100), composite materials and similar, in compliance of tolerances set by design. |
