NUMERIC CONTROLLER.

摘要

A numeric controller for controlling an NC gear cutting machine tool such as a gear hobbing machine. A feedback pulse signal from a position coder (7) coupled to a hob shaft (3) operate a shaft control circuit (14) disposed in synchronization control means (8), which controls the number of revolutions of a spindle motor (5) and a servomotor (11) to obtain a predetermined ratio of the number of revolutions between the hob shaft (3) and a C shaft (13). A first internal counter (15a) monitors the number of feedback pulses from the position coder (7) and a second internal counter (15b) monitors the number of pulses distributed to the C shaft (13). When the ratio of the number of revolutions between the hob shaft (3) and the C shaft (13) is changed, correction pulse computing means (9) computes correction pulses on the basis of the number of pulses corresponding to the revolutions of the hob shaft (3) and the C shaft (13) counted by the first and second internal counters (15a, 15b). The correction pulses are applied for controlling the C shaft (13) to change the positional relation to the hob shaft (3) for a new synchronous relation between the two shafts.