| 摘要 |
PURPOSE:To improve machining accuracy by providing a plurality of square through holes in the positions except the rotation center of a cylindrical polishing jig and inserting a rectangular solid jig to the bottom portion of which a workpiece is bonded into the through hole. CONSTITUTION:A plurality of through holes having a square section are provided in positions off of a rotation center in a cylindrical polishing jig 1. A rectangular solid polishing jig 2 on the bottom portion of which a workpiece is bonded is closely inserted into this through hole. As a polishing surface plate 3 which is coated with an abrasive material is rotated, the cylindrical jig 1 is rotated while being supported by a roller bar 5 due to the difference in frictional force caused by the difference in speed between inner and outer peripheries, while the polishing jig 2 is rotated together with the cylindrical jig 2 because of the rectangular solid body, to polish the workpiece on the bottom portion thereof. By this structure, the flatness, parallelism, and dimensional accuracy of the machining surface can be finished to the desired machining accuracy. |
