Numerical control device, machine learning device, and numerical control method

A machine learning device for learning a command value of a cutting depth, the cutting depth being a difference between a face to be machined of a workpiece before machining and the machined face after machining in a fixed vibrating direction, in vibration cutting in which a plurality of drive shafts are controlled to drive a tool and cause the tool to machine the workpiece while vibrating the tool in the vibrating direction regardless of a cutting direction, the cutting direction being a moving direction of the tool, the machine learning device comprising:

• a third processor;
• and
• a third memory to store a third program which, when executed by the third processor, performs processes of:
• observing, as state variables, machining program identification information for identifying a machining program describing procedures for controlling the drive shafts, machining path information indicating a machining path of the tool, and tool identification information for identifying the tool;
• and
• learning the cutting depth for each cutting command in the machining program in accordance with a data set created on the basis of the state variables.

A numerical control method for controlling a plurality of drive shafts to drive a tool and cause the tool to cut a workpiece while vibrating the tool in a fixed vibrating direction regardless of a cutting direction, the cutting direction being a moving direction of the tool, the numerical control method comprising:

• determining, whether or not the vibrating direction and the cutting direction are the same as each other;
• comparing, a command value of a cutting depth with an actual value of the cutting depth based on a vibration amplitude of the drive shaft when the vibrating direction and the cutting direction are not the same as each other, the cutting depth being a difference between a position of a face to be machined of the workpiece before machining and a position of the machined face after machining in the vibrating direction;
• and
• adjusting, a movement of the tool so that the actual value becomes smaller when the actual value is larger than the command value.