This application is based on and claims the benefit of priority from Japanese Patent Application No. 2019-231924, filed on 23 Dec. 2019, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a control device, a machining system, and a recording medium encoded with a program.

Related Art

Conventionally, a machine tool for machining a workpiece by fixing the workpiece to a rotating body has been known. In such a machine tool, the center of gravity of the workpiece is ideally disposed at a position where the center of gravity overlaps the axial center direction of the rotating body. With such a configuration, in the rotation of the rotating body, it is possible to suppress the occurrence of vibration or the occurrence of phase bias.

However, the center of gravity of the actual workpiece often deviates from the axial center direction of the rotating body. Therefore, it is preferable to adjust the imbalance due to the deviation in order to improve the accuracy of machining. For example, a numerical control device has been proposed which calculates the quantity and phase of the imbalance by rotating the workpiece after machining to adjust the balance using a program for balance adjustment (e.g., refer to Japanese Unexamined Patent Application, Publication No.H5-145651).

Patent Document 1: Japanese Unexamined Patent Application, Publication No. H5-145651

SUMMARY OF THE INVENTION

The numerical control device disclosed in Japanese Unexamined Patent Application, Publication No.H5-145651 is advantageous in that it is possible to adjust the workpiece based on the imbalance after machining. In this regard, it is preferable to be able to determine a change in the rotational state of the rotating body so that the balance of the rotating body to which the workpiece is fixed can be adjusted.

A first aspect of the present disclosure relates to a control device is configured to control operation of a drive unit and monitor a rotational balance of a rotating body, for a machine tool including the rotating body that is rotatable around a predetermined axial center in a state of fixing an object and on which an adjusting tool that can adjust the rotational balance is arrangeable, and the drive unit that rotates the rotating body, and the control device includes: a physical quantity acquiring unit configured to acquire at least one physical quantity indicating a rotational state of the rotating body, the physical quantity being changed in response to an adjustment of the rotational balance; a comparing unit configured to compare a plurality of physical quantities having different acquisition times; and an output unit configured to output a comparison result.

A second aspect of the present disclosure relates to a machining system including: a machine tool including a rotating body that is rotatable around a predetermined axial center in a state of fixing an object and on which an adjusting tool that can adjust a rotational balance is arrangeable, and a drive unit that rotates the rotating body; and a control device according to the first aspect.

A third aspect of the present disclosure relates to a recording medium encoded with a program that causes a computer to function as a control device configured to control operation of a drive unit and monitor a rotational balance of a rotating body, for a machine tool including the rotating body that is rotatable around a predetermined axial center in a state of fixing an object and on which an adjusting tool that can adjust the rotational balance is arrangeable, and the drive unit that rotates the rotating body, the program causing the computer to function as: a physical quantity acquiring unit configured to acquire at least one physical quantity indicating a rotational state of the rotating body, the physical quantity being changed in response to an adjustment of the rotational balance; a determining unit configured to compare a plurality of physical quantities having different, acquisition times, and determine a change in a physical quantity; and an output unit configured to output a determination result.

According to the present disclosure, it is possible to provide a control device, a machining system, and a recording medium encoded with a program, which are capable of determining a change in a rotational state of a rotating body.

