| 摘要 |
PURPOSE:To prevent spiral grooves from being blocked by cutting chips by forming both high blades for cutting the central area and low blades for cutting the rest on both sides on the bottom surface of the cylindrical portion of a cutter body, so that wide chips and narrow chips can be discharged from respective independent spiral grooves. CONSTITUTION:Spiral grooves 6, 7 are formed in the annular wall of cylindrical portion 2, and high blades 4 and low blades 5 are formed alternately at a constant interval along the circumference of the bottom surface. The high blades 4 cut a workpiece with their central portions and low blades 5 cut both sides of the groove cut in the central area. Accordingly, the cut chips are classified into three portions of different width, namely, one portion of about a half of the overall width and two portions of about a quarter of the same, and they are discharged through respective independent grooves, thus preventing the grooves from being blocked by cutting chips. |
