| 摘要 |
PURPOSE:To smoothly carry out discharge of a polishing dust and detached abrasive grains made at the time of polishing outside and improve flatness of a polished body by forming a rectilineal groove inclining a groove reaching the back surface of a grinding stone in the specified direction on the grinding surface of a plural number of flat fan-type fixed grinding stones. CONSTITUTION:A lapping disc 1 is constituted by fixing falt fan-type fixed grinding stone pieces 3 (31, 32...) on a plural number of installation pieces 7 (71, 72...) of the same shape on a circular lapping surface plate 2 and inserting bolts into bolt insertions holes respectively and fastening them. In this case, on the surface of each of the grinding stone pieces 3, rectilineal grooves 6' (61', 62'...) inclined at an angle of 10-30... in the rotational direction of the lapping disc 1 from a vertical line from the surface of this grinding stone piece 3 to an installation plate piece 7 and directed to the adjacent side surface from the lower bottom side surface of the grinding stone piece 3 are formed. Consequently, a discharging property of polishing dust and detached abrasive grains outside is heightened, catching of a polished body by the grooves 6' is eliminated, and damage of the grinding stones pieces 3 is prevented. |
