Numerical control method and numerical control device of machine tool

摘要

A numerical control device which controls a feed axis of a machine tool has a storage unit which divides a range of movement of the feed axis into a plurality of regions and stores a plurality of control parameters corresponding to the divided plurality of regions in advance, a position detection unit which detects a position of a feed axis at the time of machining a workpiece, a parameter selection unit which reads out control parameters corresponding to a divided region to which the detected feed axis position at the time of machining a workpiece belongs, and a servo control unit which controls the feed axis using the read control parameters. Due to this, it is possible to provide a numerical control method of a machine tool which realizes stable machining precision without regard as to the feed axis position and a numerical control device which conducts that method.

主权项

1. 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.