Enhanced piercing through current profiling
US8168916B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2008 |
| Grant date | May 1, 2012 |
| Priority date | — |
| Expiry date | Feb 28, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/3457
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
In general, the present invention provides a method of piercing a workpiece with a plasma arc torch of the type having a plasma gas flow path for directing a plasma gas through the torch and a secondary gas flow path for directing a secondary gas through the torch. The method comprises directing a flow of shield gas along a distal end portion of the plasma arc torch to deflect metal spatter generated from the piercing, and ramping a current provided to the plasma arc torch along a profile during piercing and controlling current ramp parameters as a function of a thickness of the workpiece and an operating current level, wherein the current ramp parameters comprise a length of time, a ramp rate, a shape factor, and a modulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.