Acoustic monitoring of cutting conditions to detect tool break events
US4636780A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1984 |
| Grant date | Jan 13, 1987 |
| Priority date | — |
| Expiry date | Oct 24, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/37525
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
This tool break detection system relies on monitoring changes in the cutting noise itself, rather than detecting the tool fracture acoustic signal. A broken tool capable of damaging the workpiece is detected, and tool break events that do not affect cutting conditions are ignored. The signal from a sensor such as an accelerometer is preprocessed to attenuate low frequency machinery noise and detect the signal energy in a band below 100 KHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic. Runout false alarms during rough surface cutting are prevented; after detection of an abrupt increase or decrease in signal level, the confirmation period to test for a persistent shift in mean level is set longer than the workpiece revolution period.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.