| 摘要 |
PROBLEM TO BE SOLVED: To provide a drill bit for drilling prepreg, which is used in a method for drilling the prepreg with a thermosetting resin composition inpregnated in a base material, and performs drilling continually more times. SOLUTION: This drill bit 10 for drilling prepreg has an axial through-hole, and is used for drilling a stack of prepreg 20 while blowing air A to a portion of a blade 12 from the through-hole 16. An indentation part 18 in a notch form but not a spiral groove communicated with the stack of the prepreg 20 to a noncontact portion in an axial direction at the time of drilling from the tip portion is formed to a column like axial element 14. The through-hole 16 is exposed to the recessed part 18, and a separate member, namely the blade 12 is jointed to a tip potion of the indentation part 18. COPYRIGHT: (C)2004,JPO
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