| 摘要 |
<p>PURPOSE: To improve the efficiency of cutting operation, and to treat even chips easily by successively repeating a process, in which an annular groove corresponding to the quantity of notching at a first stage is formed in the outer circumferential surface of an insulator, an axial groove in approximately the same quantity of notching is formed from the annular groove and a tool is moved spirally and cutting is conducted. CONSTITUTION: A tool 28 is moved to the axial center side while being rotated on the outer circumferential surface of an insulator, and an annular groove 60 in the depth of the quantity d1 of notching at a first stage is formed. The revolution of the tool 28 is stopped, and the tool 28 is moved forward by a specified distance under the state, in which the quantity d1 of notching is maintained, thus shaping an axial groove 62. The tool 28 is advanced while being turned, the quantity d1 of notching is kept, and the outer circumferential surface is cut. Accordingly, even when the quantity of one-time notching and a feed rate are increased, cut chips are formed positively in short pieces, and treatment is facilitated while the efficiency of cutting operation can be improved by largely setting the quantity of notching and the feed rate.</p> |
