| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a bulge due to an unshaven portion from occurring.SOLUTION: Cutting blades on the rear end side of a broach body includes a plurality of tooth thickness finishing blades 6 on the tip end side and a tooth trace adjustment blade 8 on the rear end side. Each tooth thickness finishing blade 6 forms a cutting blade 6C at an intersecting ridge line part between a cutting face 6A and a side face 6B facing one side among the circumferential directions, and is provided with a guide part 6D on the side face facing the other side. In the plurality of tooth thickness finishing blades 6, the guide part 6D is positioned on a spiral line L twisted around the shaft line 0 with a constant lead. The tooth thickness finishing blade 6-0 on the rear end side has a larger blade width than the tooth thickness finishing blade 6-2 on the tip end side, and the tooth trace adjustment blade 8 has a smaller blade width than the tooth thickness finishing blade 6-0 on the rear end side. Further, A guide part 8B provided on the side face facing to the other side protrudes out toward the other side beyond the spiral line L.</p> |
