To provide a drilling tool, in which the position of a blade in the diametric direction of a tool main body and its protruding quantity toward the tip of the tool main body can be simply and precisely adjusted, and a drilled hole can be formed with favorable size precision.
A recess 15 is formed at a tip part of the tool main body 12, and in a wall surface of the recess 15 diametrically outward of the tool main body 12, a cutting tool hole 17 to contain a cutting tool 31 is formed to extend in an inclined direction to an axial line O so as to gradually separate from the recess 15 toward the rear end side of the tool main body 12. At the cutting tool hole 17 on the opposite side of the recess 15, an adjusting screw 21 is provided to adjust the protruding quantity of the cutting tool 31. The cutting tool 31 comprises: an outer circumferential blade 35 directed diametrically outward of the toll main body 12; and a tip blade part 36 directed toward the tip side of the tool main body 12. In the outer circumferential blade 35, a back taper is provided to recede diametrically inward of the tool main body 12 gradually toward the rear end side of the tool main body 12.
OTSUKA TOMOJI
Tadashi Takahashi
Masakazu Aoyama
Yasuhiko Murayama
Noriko Yanai