Numerical control device and numerical control method

A numerical control device for controlling a main shaft and a drive shaft, the main shaft being a rotating shaft for an object to be machined, the drive shaft driving a tool for vibration cutting of the object the numerical control device comprising:

• a memory to store a machining program for vibration cutting of the object;
• and
• a control calculator to calculate a specific point that the tool passes during the vibration cutting on a basis of a tolerance value being an allowable error in machining of a corner of the object from a first direction to a second direction, and generate a vibration waveform of the tool indicating a movement path of the tool passing the specific point, wherein
• the control calculator generates, as the vibration waveform, a first vibration waveform in the first direction and a second vibration waveform in the second direction, corrects, on a basis of the tolerance value set by calculation of the specific point, a start timing of the second vibration waveform so that the first vibration waveform and the second vibration waveform pass the specific point at a same timing when the tolerance value is larger than 0, and controls movement and vibration of the tool in accordance with the machining program and the vibration waveform, and
• when the first vibration waveform passes the specific point a plurality of times, the timing when the first vibration waveform and the second vibration waveform pass the specific point is set from among timings when the first vibration waveform passes the specific point a plurality of times, and a start timing of the second vibration waveform is corrected on a basis of the tolerance value so that the second vibration waveform passes the specific point at the set timing.