DEVICE AND METHOD OF CONTROLLING MACHINE TOOL, TO CONTROL SYNCHRONIZED OPERATION OF SPINDLE AXIS AND FEED AXIS

摘要

A machine tool controller including a numerical control section, a spindle-axis control section and a feed-axis control section. The spindle-axis control section includes a section for making the spindle axis perform an accelerated rotation at maximum capacity from a process start position toward a target thread depth, with a maximum rotation speed set as a target value; a section for detecting a maximum acceleration during the accelerated rotation based on a rotational position; a section for detecting a residual rotation amount from a current position to the target thread depth, based on a total rotation amount and the rotational position; a section for detecting a current speed based on the rotational position; and a section for making the spindle axis perform a decelerated rotation at maximum capacity to reach the target thread depth after the accelerated rotation, based on the maximum acceleration, the residual rotation amount and the current speed.

主权项

1. A controller of a machine tool, configured to control a synchronized operation of a spindle axis and a feed axis, the controller comprising:
a numerical control section configured to prepare a spindle-axis command and a feed-axis command based on a tapping program; a spindle-axis control section configured to control a rotational motion of the spindle axis in accordance with the spindle-axis command; a rotation detecting section configured to detect a rotational position of the spindle axis; and a feed-axis control section configured to control a feed motion of the feed axis in accordance with the feed-axis command, based on the rotational position; the numerical control section comprising:
a spindle-axis command outputting section configured to obtain, from the tapping program, a total rotation amount and a maximum rotation speed of the spindle axis during a period when the spindle axis operates from a process start position to a target thread depth, and to send the total rotation amount and the maximum rotation speed as the spindle-axis command to the spindle-axis control section; the spindle-axis control section comprising:
an initial-motion control section configured to make the spindle axis perform an accelerated rotation at maximum capacity, from the process start position toward the target thread depth, with the maximum rotation speed set as a target value;a maximum-acceleration detecting section configured to detect a maximum acceleration during the accelerated rotation at maximum capacity, based on the rotational position;a residual rotation-amount detecting section configured to detect a residual rotation amount of the spindle axis during a period when the spindle axis operates from a current position to the target thread depth, based on the total rotation amount and the rotational position;a current-speed detecting section configured to detect a current speed of the spindle axis based on the rotational position; anda positioning-motion control section configured to make the spindle axis perform a decelerated rotation at maximum capacity so as to reach the target thread depth, after the accelerated rotation at maximum capacity, based on the maximum acceleration, the residual rotation amount and the current speed.