Spot welding method and spot welding apparatus
US9505078B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 16, 2011 |
| Grant date | Nov 29, 2016 |
| Priority date | — |
| Expiry date | Nov 20, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/04
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A spot welding method and a spot welding apparatus are provided. A stacked assembly of at least three workpieces is gripped between first and second welding tips. An inner workpiece positioned inside of the stacked assembly, of two of the workpieces that exhibit a maximum contact resistance in the stacked assembly, is electrically connected to a ground electrode, or to an electrode having the same polarity as the second welding tip near an outer workpiece positioned adjacent to the inner workpiece and facing outwardly from the stacked assembly, of the two workpieces. Then, electric current is applied from the first welding tip toward the second welding tip. In this case, first, the stacked assembly is pressed under a first pressing force, and then, the stacked assembly is pressed under a second pressing force which is greater than the first pressing force.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.