Device and method of controlling machine tool, to control synchronized operation of spindle axis and feed axis
First Claim
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 hardware configured as:
- 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 and based on the rotational position of the spindle axis;
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 using a maximum permissible current of a drive source from the process start position, by a velocity control in which the maximum rotation speed is set as a target value;
a maximum-acceleration detecting section configured to detect a maximum acceleration of the spindle axis 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;
a decelerating-motion control section configured to make the spindle axis perform a decelerated rotation so as to reach a predetermined intermediate rotation speed, by a velocity control, after the accelerated rotation at maximum capacity;
and a positioning-motion control section configured to make the spindle axis perform a decelerated rotation at maximum deceleration corresponding to the maximum acceleration so as to reach the target thread depth, by a position control, after the spindle axis reaches the intermediate rotation speed, based on the maximum acceleration, the residual rotation amount and the current speed;
wherein the decelerating-motion control section is configured to successively update a velocity command for the decelerated rotation by the velocity control with use of the residual rotation amount and the current speed, and to make the spindle axis perform the decelerated rotation by the successively updated velocity command so that the residual rotation amount at an instant when the spindle axis reaches the intermediate rotation speed becomes equal to a positioning rotation amount of the spindle axis required for the spindle axis to reach the target thread depth under the position control.
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Accused Products
Abstract
A controller for controlling a synchronized operation of spindle and feed axes. A spindle-axis control section includes an initial-motion control section for making a spindle axis perform an accelerated rotation at maximum capacity from a process start position; a maximum-acceleration detecting section for detecting a maximum acceleration of the spindle axis; a residual rotation-amount detecting section for detecting a residual rotation amount of the spindle axis; a current-speed detecting section for detecting a current speed of the spindle axis; a decelerating-motion control section for making the spindle axis perform a decelerated rotation at a gradually increasing deceleration so as to reach an intermediate rotation speed after the accelerated rotation; and a positioning-motion control section for making the spindle axis perform a decelerated rotation at maximum capacity so as to reach the target thread depth after reaching the intermediate rotation speed.
26 Citations
15 Claims
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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 hardware configured as:
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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 and based on the rotational position of the spindle axis; 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 using a maximum permissible current of a drive source from the process start position, by a velocity control in which the maximum rotation speed is set as a target value; a maximum-acceleration detecting section configured to detect a maximum acceleration of the spindle axis 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; a decelerating-motion control section configured to make the spindle axis perform a decelerated rotation so as to reach a predetermined intermediate rotation speed, by a velocity control, after the accelerated rotation at maximum capacity; and a positioning-motion control section configured to make the spindle axis perform a decelerated rotation at maximum deceleration corresponding to the maximum acceleration so as to reach the target thread depth, by a position control, after the spindle axis reaches the intermediate rotation speed, based on the maximum acceleration, the residual rotation amount and the current speed; wherein the decelerating-motion control section is configured to successively update a velocity command for the decelerated rotation by the velocity control with use of the residual rotation amount and the current speed, and to make the spindle axis perform the decelerated rotation by the successively updated velocity command so that the residual rotation amount at an instant when the spindle axis reaches the intermediate rotation speed becomes equal to a positioning rotation amount of the spindle axis required for the spindle axis to reach the target thread depth under the position control. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A controller of a machine tool, configured to control a synchronized operation of a spindle axis and a feed axis, the controller comprising a hardware processor configured as:
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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 and based on the rotational position of the spindle axis; the numerical control section comprising; a spindle-axis command outputting section configured to obtain, from the tapping program, a total return-rotation amount and a maximum return-rotation speed of the spindle axis during a period when the spindle axis operates from a target thread depth to a return completion position, and to send the total return-rotation amount and the maximum return-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 inverse rotation at maximum capacity using a maximum permissible current of a drive source from the target thread depth or from an initial return position at which the spindle axis has returned by a predetermined rotation number from the target thread depth, by a velocity control in which the maximum return-rotation speed is set as a target value; a maximum-acceleration detecting section configured to detect or obtain a maximum acceleration of inverse rotation of the spindle axis during a period when the spindle axis performs the accelerated inverse rotation from the target thread depth; a residual rotation-amount detecting section configured to detect a residual return-rotation amount of the spindle axis during a period when the spindle axis operates from a current position to the return completion position, based on the total return-rotation amount and the rotational position; a current-speed detecting section configured to detect a current speed of inverse rotation of the spindle axis based on the rotational position; a decelerating-motion control section configured to make the spindle axis perform a decelerated inverse rotation so as to reach a predetermined intermediate return-rotation speed, by a velocity control, after the accelerated inverse rotation at maximum capacity; and a positioning-motion control section configured to make the spindle axis perform a decelerated inverse rotation at maximum deceleration corresponding to the maximum acceleration of inverse rotation and stop at the return completion position, by a position control, after the spindle axis reaches the intermediate return-rotation speed, based on the maximum acceleration of inverse rotation, the residual return-rotation amount and the current speed of inverse rotation; wherein the decelerating-motion control section is configured to successively update a velocity command for the decelerated inverse rotation by the velocity control with use of the residual return-rotation amount and the current speed of inverse rotation, and to make the spindle axis perform the decelerated inverse rotation by the successively updated velocity command so that the residual return-rotation amount at an instant when the spindle axis reaches the intermediate return-rotation speed becomes equal to a positioning return-rotation amount of the spindle axis required for the spindle axis to stop at the return completion position under the position control.
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14. A method of controlling a machine tool, configured to control a synchronized operation of a spindle axis and a feed axis, the method comprising the steps, executed by a controller, of:
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obtaining, from a 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; making the spindle axis perform an accelerated rotation at maximum capacity using a maximum permissible current of a drive source from the process start position, by a velocity control in which the maximum rotation speed is set as a target value; detecting a maximum acceleration of the spindle axis during the accelerated rotation at maximum capacity, based on a rotational position feedback of the spindle axis; detecting 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 feedback; detecting a current speed of the spindle axis based on the rotational position feedback; making the spindle axis perform a decelerated rotation so as to reach a predetermined intermediate rotation speed, by a velocity control, after the accelerated rotation at maximum capacity; and making the spindle axis perform a decelerated rotation at maximum deceleration corresponding to the maximum acceleration so as to reach the target thread depth, by a position control, after the spindle axis reaches the intermediate rotation speed, based on the maximum acceleration, the residual rotation amount and the current speed; wherein the step of making the spindle axis reach the intermediate rotation speed includes the step of successively updating a velocity command for the decelerated rotation by the velocity control with use of the residual rotation amount and the current speed, and making the spindle axis perform the decelerated rotation by the successively updated velocity command so that the residual rotation amount at an instant when the spindle axis reaches the intermediate rotation speed becomes equal to a positioning rotation amount of the spindle axis required for the spindle axis to reach the target thread depth under the position control, and wherein the method further comprises the steps, executed by the controller, of; preparing a feed-axis command based on the tapping program; and controlling a feed motion of the feed axis in accordance with the feed-axis command and based on the rotational position feedback of the spindle axis.
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15. A method of controlling a machine tool, configured to control a synchronized operation of a spindle axis and a feed axis, the method comprising the steps, executed by a controller, of:
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obtaining, from a tapping program, a total return-rotation amount and a maximum return-rotation speed of the spindle axis during a period when the spindle axis operates from a target thread depth to a return completion position; making the spindle axis perform an accelerated inverse rotation at maximum capacity using a maximum permissible current of a drive source from the target thread depth or from an initial return position at which the spindle axis has returned by a predetermined rotation number from the target thread depth, by a velocity control in which the maximum return-rotation speed is set as a target value; detecting or obtaining a maximum acceleration of inverse rotation of the spindle axis during a period when the spindle axis performs the accelerated inverse rotation from the target thread depth; detecting a residual return-rotation amount of the spindle axis during a period when the spindle axis operates from a current position to the return completion position, based on the total return-rotation amount and a rotational position feedback of the spindle axis; detecting a current speed of inverse rotation of the spindle axis based on the rotational position feedback; making the spindle axis perform a decelerated inverse rotation so as to reach a predetermined intermediate return-rotation speed, by a velocity control, after the accelerated inverse rotation at maximum capacity; and making the spindle axis perform a decelerated inverse rotation at maximum deceleration corresponding to the maximum acceleration of inverse rotation and stop at the return completion position, by a position control, after the spindle axis reaches the intermediate return-rotation speed, based on the maximum acceleration of inverse rotation, the residual return-rotation amount and the current speed of inverse rotation; wherein the step of making the spindle axis reach the intermediate rotation speed includes the step of successively updating a velocity command for the decelerated inverse rotation by the velocity control with use of the residual return-rotation amount and the current speed of inverse rotation, and making the spindle axis perform the decelerated inverse rotation by the successively updated velocity command so that the residual return-rotation amount at an instant when the spindle axis reaches the intermediate return-rotation speed becomes equal to a positioning return-rotation amount of the spindle axis required for the spindle axis to stop at the return completion position under the position control, and wherein the method further comprises the steps, executed by the controller, of; preparing a feed-axis command based on the tapping program; and controlling a feed motion of the feed axis in accordance with the feed-axis command and based on the rotational position feedback of the spindle axis.
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Specification