| 摘要 |
PURPOSE:To surely decide the generation of the over-movement of a polishing belt without using the switch class likely to cause a trouble by deciding the generation of the over-movement of a polishing belt from the lapse time of from a normal reversal movement at the reversal position by using a computer. CONSTITUTION:The respective necessary time in the reciprocating movement of a polishing belt 4 between two reversal positions is measured and the necessary mean times t1, t2 are calculated by a computer 16. The respective ordinary moving speed v1, V2 are calculated from these calculation values t1, t2, the necessary times t3, t4 spent in reaching an allowable limit position over the reversal position of the other part after reversing at the reversal position of one part are calculated based on this calculation value v1, v2 and set as the respective initial set value at both sides of the polishing belt moving area. Then at the time when the time lapsed in the state of no detection being made reaching to the succeeding reversal position from the time reaching to the reversal position of one part, reaches the initial set value t3, t4 it is decided that the over-movement of the polishing belt 4 is generated. |
