Plasma torch and system with electromagnetic shield assist mechanism

摘要

A plasma arc system includes a plasma torch having a torch nozzle with an opening at a distal end for a plasma jet to exit. An electromagnetic shield cap is disposed near the distal end of the torch nozzle with the shield cap having an opening that is coaxial with the opening of the torch nozzle. A plasma cutting power source supplies current to the torch to create the plasma jet. A magnetic field power source provides a current to the electromagnetic shield cap to generate a magnetic field near the plasma jet to focus the plasma jet as the plasma jet exits the torch nozzle. A controller synchronizes operation of the power sources during a transition from a piercing operation to a cutting operation.

主权项

1. A plasma arc system, the system comprising:
a plasma torch, the plasma torch having a torch nozzle with an opening at a distal end for a plasma jet to exit the plasma torch; an electromagnetic shield cap disposed near the distal end of the torch nozzle, the electromagnetic shield cap having an opening that is coaxial with the opening of the torch nozzle; a plasma cutting power source to supply current to the torch to create the plasma jet; a magnetic field power source to provide a current to the electromagnetic shield cap to generate a magnetic field near the plasma jet to focus the plasma jet as the plasma jet exits the torch nozzle; and a controller to synchronize operation of the plasma cutting power source and operation of the magnetic field power source during a transition from a piercing operation that burns through a workpiece to a cutting operation that cuts the workpiece, wherein the magnetic field ramps from a background level value to a peak level value prior to the transition from the piercing operation to the cutting operation and the magnetic field reaches the peak level value at a same time as the transition from the piercing operation to the cutting operation.