Apparatus for monitoring spot welding process and method of the same
US6335504B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2000 |
| Grant date | Jan 1, 2002 |
| Priority date | — |
| Expiry date | Dec 15, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K11/257
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The present invention discloses an apparatus and a method for monitoring the quality of a spot welding process. The measured electric current and voltage signals between electrodes of a spot welding system are converted into digital data first. Then the two digital data are processed to obtain their complex forms via Hillbert transform respectively to construct their imaginary part. Finally, the electrical impedance Zin is obtained from dividing the complex form of digital voltage by the complex form of digital current. The electrical impedance Zin can be applied to compare with historical data to diagnose the quality of spot-welding points.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.