| 摘要 |
PURPOSE:To improve surface roughness of a plate and accuracy of its flatness, by cutting one side surface of the thin plate, providing a sucking surface of shape, aligned to a warp caused at the cutting, in a vacuum chuck, sucking the thin plate to said vacuum chuck and cutting the other side surface of the plate along said sucking surface. CONSTITUTION:In the first process, a thin plate W is sucked to a vacuum chuck 12, having a sucking surface 12a vertical to a main spindle axial line, and one side surface A of the plate is machined by a cutting tool T. After the cutting, if the thin plate is removed from the chuck 12, a warp is caused in the other side surface B not yet machined. In the second process, the thin plate W is sucked to a vacuum chuck 12, having a sucking surface 12b aligned to said warp, and the cutting tool T is shifted to cut the other side surface B. An equal machining condition is applied to that of the first machining process, especially in its depth of cut, the same amount of cut is applied, in this way, residual stress in the side A is equalized to residual stress in the side B, and the curved warp can be reduced. |
