GB1174680A - Improvements in or relating to Automatic Control Devices for Gear Teeth Grinding Machines - Google Patents

Abstract

1,174,680. Grinding. ZAHNRADFABRIK FRIEDRICHSHAFEN A.G. 4 Dec., 1967 [17 Dec., 1966], No. 54985/67. Heading B3D. A control device in a machine for grinding gears and splined shafts comprises mechanical path measurement means for the selective movement of a grinding spindle carrier 1 into a grinding position corresponding to the respective grinding allowance and into a position for dressing the grinding wheel. As shown, pins 14a-14d of different lengths are inserted into holes in a programme disc 13 to selectively actuate switches 15a-15d when driven by a feed motor 11; each grinding allowance is determined by the spacing of pins 14a and each dressing operation is determined by a pin 14b. Before grinding, the feed motor 11 simultaneously rotates the programme disc 13 clockwise and slides a limit nut 9 to the left within a piston 8, the switch 15c being actuated and the piston moved to the left by hydraulic pressure; a feed wedge 6 attached to the piston causes the grinding spindle carrier 1 to be raised. After a predetermined number of strokes of the horizontally reciprocating work-table, a counting mechanism switches on the feed motor 11 to move the feed wedge to the right by an amount corresponding to the first grinding allowance and to initiate the selected work operations. After the required number of teeth have been ground as set by the counting mechanism, the work operation is repeated on the same teeth at the next grinding allowance. If a pin 14b encounters a switch 15b then a wheel dressing operation is initiated, the piston 8 being moved by hydraulic pressure to the right over the nut 9 to lower the grinding spindle carrier 1. A motor 17 operating through a clutch 19 feeds the amount to be dressed. After the dressing operation, the piston is returned by a signal from the dressing apparatus to re-set the grinding spindle carrier to the position occupied before dressing less the feed amount which the nut 9 has introduced in the meantime. After sparking out, the work-table is stopped and the grinding spindle carrier 1 and the programme disc 13 are automatically re-set by the switch 15d to the position selected by the pin 14c. A hand wheel 18 is used to adjust the carrier 1 for a different workpiece or grinding wheel. In an alternative arrangement of the programme disc, the pins are of equal length and are disposed radially on a thicker disc.