Method and system for welding workpieces
US8455784B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 2008 |
| Grant date | Jun 4, 2013 |
| Priority date | — |
| Expiry date | Apr 4, 2032 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K31/125
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of welding two or more workpieces employing a motion-controlled electrode that reduces temperature and residual stresses at a workpiece-to-electrode interface is disclosed. During a first period of time, a first electrode force is applied to the workpieces to be welded, and a weld current is applied that causes heating of an associated workpiece-to-workpiece faying surface, the first electrode force being applied at a first electrode stroke. A temperature of the faying surface indicative of a weld nugget formation thereat is determined, and in response thereto the electrode force is reduced to a second level during a second period of time while maintaining a constant electrode stroke. During a third period of time, the electrode force is further reduced to a third level while simultaneously reducing the electrode stroke to a second level. Welding is stopped after the third period of time, resulting in a weld joint having reduced residual stresses and reduced likelihood of stress crack formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.