| 摘要 |
PROBLEM TO BE SOLVED: To reduce manufacturing cost by efficiently manufacturing a spiral fluted tap different in recess shape of a leading flank and a following flank. SOLUTION: In a screw grinding wheel 42, a first grinding crest 32 and a second grinding crest 34 for finish grinding are provided at a distance in the axial direction by a space 2P two times as large as the pitch P of a thread 14. The first grinding crest 32 is determined in its sectional form to grind only the leading flank 26, and on the other hand, the second grinding crest 34 is determined in its sectional form to grind only the following flank 28, whereby timing of grinding is shifted between both flanks 26, 28 by the torsion of the spiral flute, so that the leading flank 26 and the following flank 28 are provided with the recess different in shape only by periodically approaching and separating the screw grinding wheel according to the cam shape 44. COPYRIGHT: (C)2007,JPO&INPIT |
