| 摘要 |
PURPOSE:To decrease greatly the resetting time to an original position of a mobile object by shifting this object at a high speed for period during which the shift direction of the mobile object is inverted and then the 2nd signal is turned off. CONSTITUTION:A grindstone stand 11 of a mobile object can be moved forward and backward to a work W on a bed 10, and a feed screw 12 which is fitted to the stand 11 is moved back and forth by a servo motor 13. While numerical controller 15 distributes command pulses to a drive circuit 16 of the motor 13. When an original position resetting command ORC is given from outside, the original resetting action of the stand 11 is controlled together with a dog 18 based on the signals supplied from a limit switch 17 and a position detectors 19 for a magnetism generator 21, a detection head 20, etc. When the stand 11 is moved back to its original position, the 1st signal CS1 of a comparator 23 is set a high level. Then the 2nd signal CS2 of a comparator 24 is set at a high level when the stage 11 is moved back to a flow detecting point. The minus pulses having a fixed delay feed speed are distributed while the signal CS2 is kept off. Then the distribution of these pulses is discontinued when the signal CS1 is turned off. |
