Patent ID: 9122268
Filing Date: 2015-09-01
Classification: G05B

Abstract:
1. A monitoring method for monitoring a rotation speed of a rotary shaft in a machine tool, the machine tool including the rotary shaft that is mounted with one of a tool and a workpiece and driven by a motor, and a rotation speed fluctuating unit that continuously fluctuates the rotation speed of the rotary shaft at an arbitrary pattern, and a fluctuating condition of the rotation speed caused by the rotation speed fluctuating unit is monitored on a display section, the monitoring method comprising steps of: generating and displaying a fluctuation diagram that shows relationship between a fluctuation amplitude and a fluctuation period for the rotation speed on the display section; displaying a current fluctuation position on the fluctuation diagram; determining and displaying a settable range for the fluctuation amplitude and the fluctuation period on the fluctuation diagram; determining and displaying on the fluctuation diagram at least one of an optimal fluctuation period based on Equation (1) and an optimal range of the fluctuation period based on Equation (2), wherein where, P P T: rotation period of rotary shaft [s], and a, a changing the fluctuation period of the rotary shaft to one of the optimal fluctuation period and a fluctuation period value within the optimal range of the fluctuation period to suppress regenerative chatter vibration.