DRILL BIT STRUCTURE WITH IMPROVED RIGIDITY, WHICH HAS THE SAME PERFORMANCE OF REMOVING CHIPS AS NORMAL DRILL BITS

摘要

PURPOSE: A drill bit structure is provided to improve the performance of removing chips and flute spaces while two torsion grooves join at the end part of a cutting part, and formed into one torsion groove.;CONSTITUTION: A drill bit structure comprises drill handle part(12) and a cutting part(16). The cutting part is connected to the drill handle part. The cutting part comprises a first torsion groove(20) and a second torsion groove(22). The first and second torsion grooves are formed into the spiral shape at the end part of a drill. One or more front torsion angles(&thgr;2) and rear torsion angles(&thgr;3) are formed in the first and second torsion grooves. The second torsion groove is symmetrically separated from the first torsion groove. The second torsion groove having the rear torsion angle is gradually connected to the first torsion groove at the end part.;COPYRIGHT KIPO 2012