JPS5642807A - Original point resetting method of nc machine tool - Google Patents

Abstract

PURPOSE: To secure a high-accuracy resetting of the original point in a short time, by switching twice the direction of shift and then securing a stop at the accurate original point in a minute speed for the machine tool and in the final process.

CONSTITUTION: The speed is slowed down once to the medium velocity Vm not directly to the minute velocity Vl from the high velocity Vh at the time point A when the coarse original point position detecting limit switch 6 is turned on. Then the speed is slowed down more to the original point. And a stop control is given to the table 4 when the position detector 8 delivers the 1-turn detection signal. However, it is difficult to give a high-accuracy stop at the accurate original point B since the shifting has been given in the mediun velocity Vm, and thus the actual stop position is at C which is advanced more. In this connection, the shift is given in the opposite direction in the velocity Vl. This return extent is set to a range during which the 1-turn signal of the detector 6 is turned off, i.e. the returning reaches the position of D. At the position D, the table 4 is turned in a different direction to be shifted toward the original point in the velocity Vl. The table is then stopped at the time point B when the 1-turn signal of the detector 8 is turned on. Thus an accurate stopping is secured for the table 4 at the accurate original position.

COPYRIGHT: (C)1981,JPO&Japio