| 摘要 |
<p>Method and apparatus for detecting tool breakage rely on specific cutting resistance change patterns occurring on tool breakage. By comparing a stored standard cutting resistance change pattern, corresponding to a tool breakage, with cutting resistance change patterns actually occurring as the tool machines a workpiece, tool breakage ist detected. …<??>For example, cutting resistance at tool breakage may suffer a temporary reduction before rising to a new higher value. …<??>For example, cutting resistance is sampled at regular intervals (period of pulses SP), change in resistance between samples compared with a fixed value ( sigma ) and the results coded in dependence upon the change being greater than the fixed value (code "1"), less than the negation (- sigma ) of the fixed value (code "-1"), or lying between the fixed value ( sigma ) and its negation (- sigma ) (code "0"). A code value sequence (e.g. -1,1,1,1) indicative of cutting resistance change pattern is provided and compared with the standard change pattern (e.g. -1,1,1,1) similarly coded. …<??>The method and apparatus can be used in numerically controlled machine tools.</p> |
