Numerical control method and numerical control device of machine tool

A numerical control method which controls a feed axis of a machine tool, which reads and interprets a machining program, issues position commands and speed commands from a distributed control unit to a servo controller, and issues torque commands and current commands to a feed axis motor drive unit on the basis of the position commands and speed commands, said numerical control method of a machine tool comprising steps of:

• dividing a range of movement of the feed axis into a plurality of regions and storing in advance a plurality of control parameters corresponding to said divided plurality of regions and used by the servo controller,
• analyzing a machining path from the machining program of said machine tool,
• reading out control parameters corresponding to a region selected from the divided plurality of regions, determined in accordance with said machining path from said stored plurality of control parameters, the selected region being a region in which the analyzed machine path is the longest, a region in which a center of an arc shape of the analyzed machine path is located, or a region in which a machining start point of the analyzed machine path is located, and
• servo controlling the torque commands and current commands to be sent to the feed axis motor drive unit using the read-out control parameters while the read-out control parameters are inputted to the servo controller.