Numerical control device including tapping pitch data group memory

DETAILED DESCRIPTION An object of this invention is to eliminate the above-described difficulties accompanying a conventional NC device.
More specifically, an object of the invention is to provide an NC device which is provided with a memory which stores data representing the tapping values of tapping tools, as a data group for each spindle head, so that the average pitch of the tapping tools is automatically calculated to move the feed shaft.
An NC device according to the invention comprises a tapping pitch data group memory which stores data representing the tapping pitches of tapping tools as a data group for every spindle head, so that, when a tool number is specified according to a machining program, the corresponding data group is read from the tapping pitch data group memory, and the average value of the data group thus read is automatically calculated, stored in an average tapping pitch data memory, and utilized to optionally feed the spindle most suitably with respect to rotation of the tapping tools.
With the NC device according to the invention, upon specification of a tool number according to a machining program, the data group corresponding to the tool number thus specified is read from the tapping pitch data group memory in which a plurality of data groups have been stored, and the average pitch thereof is automatically calculated and utilized, so that the spindle is fed at the most suitable speed.