Method of Machining Workpiece Using Machine Tool, and Machine Tool

摘要

A machine tool includes a bed supported on a ground by supporting jigs, a table movable in an X-axis direction, a spindle head movable in a Y-axis direction, a quill provided to be movable in a Z-axis direction, a spindle supported by the quill to be rotatable about its axis, feed mechanisms for moving the table and the like in the axis directions, and a numerical controller controlling operation of the feed mechanisms, and the numerical controller is configured to calculate motion errors based on load values acting on the supporting jigs by a motion locus estimator, an influence coefficient storage, a motion error calculator, and a motion locus storage, generate a correction signal for compensating for the motion errors by a position corrector, and add the generated correction signals to a position control signal transmitted from a position generator to a position controller.

主权项

1. A method of machining a workpiece with a machine tool supported by a plurality of supporting jigs having an adjusting mechanism for adjusting a vertical support position and a load cell detecting a support load, comprising:
estimating, based on the support loads detected by the load cells of the supporting jigs, a motion locus of relative motion of a tool attached to the machine tool and the workpiece; calculating motion errors between the estimated motion locus and a preset reference motion locus at predetermined intervals in a motion direction; correcting the relative motion of the tool and the workpiece based on the calculated motion errors so as to compensate for the motion errors, and then machining the workpiece; and emitting an alarm at least when a maximum value of the calculated motion errors exceeds a predetermined reference value or when a variation value of the motion errors in the motion direction exceeds a predetermined reference value.