Control apparatus for tapping

A control apparatus configured to control synchronized operation of a spindle axis and a feed axis of a machine tool, the control apparatus comprising:

• a rotation detector configured to detect a rotation position of the spindle axis;
• and
• at least one processor configured to:
• to create a spindle axis command and a feed axis command according to a tapping program;
• control rotational operation of the spindle axis according to the spindle axis command;
• control feeding operation of the feed axis according to the feed axis command on a basis of the rotation position,
• wherein the at least one processor includes, in the spindle axis command, a speed command value during return that does not depend on maximum rotation speed during machining of the spindle axis and that is higher than the maximum rotation speed during machining, as a command of return operation for returning to a machining start position from a target screw depth, and
• wherein the at least one processor is further configured to:
• determine whether the tapping program specifies a designated maximum rotation speed during return of the spindle axis, and
• when the tapping program does not specify the designated maximum rotation speed during return of the spindle axis, control the spindle to rotate at a predetermined maximum rotation speed during return of the spindle axis,
• when the tapping program specifies the designated maximum rotation speed during return of the spindle axis:
• control the spindle to rotate at the designated maximum rotation speed during return of the spindle axis when the predetermined maximum rotation speed is greater than the designated maximum rotation speed, and
• control the spindle to rotate at the predetermined maximum rotation speed during return of the spindle axis when the predetermined maximum rotation speed is not greater than the designated maximum rotation speed.