| 摘要 |
PROBLEM TO BE SOLVED: To provide a spiral drill which is not perturbed by a strong load due to impact in the axial direction even at the time of drilling a hole. SOLUTION: A rotating stroke spiral drill is furnished with a shaft 1, the shaft 1 has at least one piece of a main carrier groove (4, 5) extending spirally on an outer covering 2 for drill chips, has at least one piece of a cemented carbide cutter 7 formed on an integrated cutting plate 6 and a foot part 10 of the cutting plate 6 is roughly fixed in a through groove 9 extending along a diameter of the shaft 1 on an end part 3 of the shaft 1. The foot part 10 of the cutting plate 6 is reinforced in an diametrical region, especially in a central region 11 of an extended part in the longitudinal direction, and its section has at least one roughly circular arc shaped curve 12. The through groove 9 on the end part 3 of the shaft 1 has a recessed part 13 formed in correspondence with a reinforcing member of the cutting plate 6. In this way, the foot part 10 of the cutting plate 6 is centered on the end part 3 of the shaft 1 by shape connection. |
