PURPOSE: To shorten the cycle time by setting the initial position of each taper correction to a position which is retracted by a predetermined distance, and by displacing a housing for a preparatory side magnetic shaft in the advance direction at the retracted position so as to always shorten the taper compensation stroke by a constant value.
CONSTITUTION: When a servo-motor 22 is rotated so as that an elevatable slide member 27 is elevated by a predetermined value by means of ball-and- screw mechanisms 24, 25, a coupling part 19 of a slide member 15 is elevated by means of a shaft pin 28, and accordingly, a link 18 is rotated. Further, a grindstone shaft housing 7 is pushed forward by means of a linear guide 13. Accordingly, the grindstone shaft housing 7 is tilted about a resilient flexible part 11 as a fulcrum, and accordingly, one end part of a grindstone shaft 5 near to the grindstone shaft housing 7 is displaced by a compensating value corresponding to the degree of rotation of the servemotor 22. Accordingly, the grindstone shaft 5 is tilted reversely by a value corresponding to the degree of a taper so that a taper during cutting is removed. In this phase, the position of each initiation of correction for the taper is set at a position which is retracted from the taper sizing position of a workpiece before processing.
YAMAUCHI TADASHI
NONOYAMA MAKOTO
