Chattering detection method for machine tool
AssigneeJtekt Corporation
InventorsToshiyuki OKITA, Ryota Tanase, Shigeru Matsunaga
Life of this patent
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Abstract
Reference phase variation values σk1 to σKn, each of which is a variation among a plurality of phases that occur during non-machining and phase variation values σ1 to σn, each of which is a variation among a plurality of phases that occur during machining are detected from measured vibration with the use of a chattering detector that is used to calculate phases of a desired number (n) of frequencies. If σKi−σi is smaller than a determination value TK, it is determined that chattering having a frequency i is occurring.
Claims3
A chattering detection method for detecting occurrence of chattering that occurs when a workpiece is machined by a tool, wherein it is determined that chattering is occurring, if a difference between a first phase variation value calculated in a first phase variation detection process and a second phase variation value calculated in a second phase variation detection process is equal to or larger than a predetermined value,
- the first phase variation detection process and the second phase variation detection process include:
- a first step of measuring a vibration and calculating a phase of a frequency in a frequency range by executing a Fourier analysis on a vibration in a time domain;
- a second step of measuring the vibration a predetermined time after the first step and then calculating a phase of a frequency in the frequency range by executing a Fourier analysis on the vibration in a time domain;
- a third step of calculating a phase difference between the phase of the vibration calculated in the first step, which has a predetermined frequency, and the phase of the vibration calculated in the second step, which has the predetermined frequency;
- and
- a fourth step of calculating a variation among multiple phase differences that are calculated by repeating the second step and the third step for a predetermined number of times.
Dependencies are inferred from the claim text.