Tool break detecting method and system preventing false alarms due to rough surfaces
US4849741A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 1988 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Jan 13, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B19/4065
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Substantial cutting condition changes which occur in intermittent bursts as rough surfaced workpieces are turned generate specific vibration signal signatures known as the runout condition. Either an upper or a lower threshold is set and all mean signal samples are compared with the threshold value. When the mean cutting noise exceeds the upper threshold or stays below the lower threshold for a preset number of signal samples, a tool break alarm is generated. Techniques are given to reduce false alarms on runout during initial rough surface cuts. The system comprises an accelerometer or other sensor whose signal is processed to attenuate lower frequency machinery noise and to detect the signal energy in a band below 100 kHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.