| 摘要 |
<p>A plasma arc torch system includes a plasma arc torch and a positioning apparatus for automated processing of workpieces. In order to maintain consistent cut quality, a controller maintains arc voltage at a predetermined reference value by controlling a standoff between the torch and the workpiece, moving the torch relative to the workpiece at a rate which increases with an increase in the deviation to minimize the deviation, and clamping the rate of torch movement relative to the workpiece when the deviation exceeds a predetermined value. To prevent a contact between the torch and workpiece during kerf crossings and to maintain an optimum standoff during acceleration and deceleration, standoff control override algorithms are implemented in the controller. Additionally, a contact sensing apparatus is provided to automatically retract the torch in the event of contact with the workpiece during processing.</p> |
