| 摘要 |
PURPOSE:To increase mounting rigidity of a cutting edge tip and to further improve mounting accuracy to a main body part of a drilling tool performing trepanning work, by mounting the cutting edge tip to an annular cutting head. CONSTITUTION:An engaging part 4b of a cutting head 4 is engaged to a hollowed part 1a of a main body part 1, and the cutting head 4 is fixed to the main body part 1 by a bolt. And then a stem part 2 provided in a rear end of the main body 1 is mounted to a machine tool, and this head 4 is rotated, then a work is performed with trepanning drilling by a plurality of cutting edge tips 3 mounted circumferentially to the cutting head 4 with a required interval apart. At this time, oil is fed to the cutting edge tip 3 from a feed oil device 11 through an oil line, simultaneously a chip is discharged to the outside through a chip discharge groove 9 of the cutting head 4 and a groove 10 in the main body 1. |
