| 摘要 |
PURPOSE: To save space and time by conducting a single clamping work by a single device by holding a crank shaft or the like between centers, machining both end part circumferential surfaces and a radial surface, and stabilizing middle zone machining by both end claming means applied in radial directions. CONSTITUTION: An end part zone 3 of a work 1 is held by a centering tip part 9 to be driven by a jaw 11 of a jaw chuck 6, and an end part zone 2 is held by the centering tip part 9 to be machined by a tool 12. After that, jaws 10, 11 on jaw chucks 5, 6 are moved radially outward, the end part zone 2 is driven by the jaw 10 to be clamped by synchronous axial move of centering tip parts 8, 9, and the end part zone 3 is held and machined only by the centering tip part 9. After both end part zones 2, 3 are machined, the end part zone 3 is clamped by the jaw 11 by axial move of the jaw chuck 6 in relation to the centering tip part 9, sufficiently stable clamping is conducted to subsequent machining to a middle zone 4, and useless time in machining by various matching devices and clamping can be eliminated. |
