| 摘要 |
PURPOSE:To extend the life and make a large broaching machine unnecessary by arranging a groove width direction cutting section having a uniform cutting edge thickness from the tip and a gradually increasing cutting edge height, a groove thickness direction cutting section having a gradually increasing wedge thickness, and a finish cutting section having no notch in the groove thickness direction. CONSTITUTION:When a braoch is moved in the arrow direction 4, first, side walls 2a, 2b are cut by a groove width direction cutting section 11b in the groove thickness direction and are machined in the groove width direction via the notch delta in the groove width direction, and the curl direction of chips is made the groove thickness direction at a right angle to the curl direction of chips generated by a broach 6. Therefore, a chip pocket can be formed large, the cutting force is not increased even if large notches are applied in the groove width direction and the groove thickness direction, and the most abrasive cutting edge tip 15 cuts the interior of the surface hardened layer. Next, the side wall is machined by a groove thickness direction cutting section 11c in the groove thickness direction, and finally the groove surface is finished by a finish cutting section 11d. Accordingly, the cutting force is not increased even if a large notch is applied, and the cutting edge tip can cut the interior of the surface hardened layer, thus the life can be extended. |
