| 摘要 |
PURPOSE:To increase the rigidity in a stop mode and to improve the stop accuracy in a simple constitution by using an inverter motor to perform the speed control of a main spindle and the stop control for fixed position of the main shaft and therefore eliminating the use of a speed detector of a pulse generator, etc. CONSTITUTION:An inverter 103r which controls a main spindle motor 104 is provided to a speed control circuit using the main spindle orientation. An arithmetic part 103a delivers a speed deviation ER between a command speed CV and a real speed AV of a speed arithmetic circuit 103t. This deviation ER is turned into a slip pulse PS of frequency through a V/F converter 103c and counted for a prescribed period of time by a counter 103d to be applied to a microcomputer 103e. This computer delivers a position deviation signal, and this deviation signal is processed by a multiplication type digital switching circuit 103k and then applied to the inverter 103r through a pulse width modulation circuit 103m. Then the speed control of the main spindle and the stop control for fixed position of the main spindle are carried out by the inverter 103r. This can eliminate the use of a speed detector of a pulse generator, etc. and therefore improves the stop accuracy in a simple constitution. |
