| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive driller with superior diametral size, circularity, cylindricity, surface roughness and positional accuracy, capable of drilling in a more shorter time. SOLUTION: In a tool 10, an end mill cutting edge 11 with a superior positional accuracy is provided at its tip (a lower end in the figure), and a reamer cutting edge 12 is provided continuously with the end mill cutting edge 11. First, the position of a prepared hole 4 is corrected by shaving the inner circumferential face of the prepared hole 4 by the tip 11a of the end mill cutting edge 11. Then the tip of the reamer cutting edge 12 bites into a portion of a chamfer 4b of a work 2. At this point, since the inner circumferential face of the prepared hole 4 is shaved by the tip 11a of the end mill cutting edge 11 and the tool 10 is guided by the tip 11a of the end mill cutting edge 11, the rigidity of the tool 10 is enhanced. Consequently, the positional deviation of the tool 10 or the bend of the tool 10 is prevented, and the positional accuracy by the end mill cutting edge 11 is maintained with high accuracy. COPYRIGHT: (C)2003,JPO
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