| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a scribing wheel for forming a hollow hole, and a method for forming the hollow hole in which the external force required on hollowing is small, the hollow hole can be formed into a neat state where a fine convex/concave or a break of a shell shape is not generated on an inner peripheral edge, and a horizontal crack is small.SOLUTION: The hollow hole is formed by hollowing after forming a scribe line of a closed curve line shape by using the scribing wheel for forming the hollow hole in which a plurality of grooves are formed with a predetermined interval along a blade tip-ridge line of the scribing wheel of a disc shape, and a bottom part of the groove extends to the direction inclining with a predetermined degreeθ1 relative to the blade tip-ridge line in a contact face of the blade tip-ridge line.</p> |
