| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polishing device capable of effectively carrying out highly smooth bowl feed polishing in a short time. SOLUTION: A ring shaped ventilation pipe 7 having many vent holes which are connected to an air pump 9 through the medium of a conduit 8 inside a bowl 1 is mounted with vent holes faced downward. An air pump 9 is controlled with a CPU 10 so as to gradually decrease an airflow rate fed into the ring shaped ventilation pipe 7 with the passage of time. When starting polishing, abrasives precipitating at the bottom of the bowl 1 are stirred up by air (air bubbles) 15 jetted forcibly out of vent holes of the ring shaped ventilation pipe 7, whereby a heavy and coarse abrasive particle is also provided to the fitting surface between a polishing plate 3 and a work piece 5. Since the airflow rate is decreased with the passage of time, particles precipitate gradually on the bottom of the bowl from heavier and coarser particle. Therefore, a particle diameter of a polishing particle supplied to the fitting surface between a polishing plate 3 and a work piece 5 is gradually changed from large to minute by the reducing airflow rate decreasing with the passage of time. |
