Numerical control device for controlling five-axis processing machine

A numerical control device configured to control a five-axis processing machine including three linear axes and two rotation axes and configured to process a workpiece attached to a table, the numerical control device comprising:

• an instruction reading unit configured to read a movement path instruction of the linear axis, a relative movement speed instruction between the workpiece and a tool, and a tool length and a tool-direction instruction as the tool direction with respect to the table;
• a tool-direction correction tolerance setting unit configured to set a tool-direction correction tolerance as a threshold value for correcting the tool direction;
• a tool-direction instruction correction unit configured to correct the tool-direction instruction so that the tool-direction instruction becomes within the tool-direction correction tolerance;
• an interpolation unit configured to obtain each axis position every interpolation period so that a tool center point moves along an instructed movement path at an instructed relative movement speed based on the relative movement speed instruction, the movement path instruction, and the tool-direction instruction corrected by the tool-direction instruction correction unit;
• and
• a unit configured to drive each axis motor so that the axis motor moves to each axis position obtained by the interpolation unit.