Nozzle for a plasma torch head, laser cutting head or plasma laser cutting head, arrangement composed of such a nozzle and of a nozzle protection cap, arrangement composed of such a nozzle and of an electrode, plasma torch head, laser cutting head or plasma laser cutting head having such a nozzle and/or having such an arrangement, plasma torch comprising such a plasma torch head, laser cutting head comprising such a nozzle and/or such an arrangement, plasma laser cutting head comprising such a nozzle and/or such an arrangement, method for plasma cutting, method for laser cutting and method for plasma laser cutting using the same.

Techniques for extinguishing a plasma arc in a blowback plasma torch are provided. The plasma arc can be extinguished by bringing the electrode into contact with the nozzle and out of contact with the nozzle while the power supply and flow of gas are left on. In particular, while current is flowing through the electrode, the electrode may be brought into contact with the nozzle to extinguish the plasma arc.

In some aspects, methods for limiting damage to a plasma arc torch body resulting from a consumable failure within the torch can include determining a specified conductivity parameter set point of a current to be provided to the plasma arc torch for a material processing operation; measuring a detected conductivity parameter of plasma arc current being provided to the plasma torch to perform the material processing operation; comparing the specified conductivity parameter set point to the detected conductivity parameter of plasma arc current and calculating an error term signal; and based on a determination that the error term signal exceeds a threshold amount, initiating a plasma arc shut down sequence to extinguish the plasma arc to limit damage to the plasma arc torch body.

In some aspects, methods of initiating a plasma arc of a plasma arc torch to pierce a workpiece and detecting plasma piercing through the workpiece to begin a cutting sequence can include calculating a pulse width modulation characteristic of an electrical signal associated with a plasma arc between an electrode of a plasma arc torch and a workpiece to be processed; monitoring the characteristic during operation of the torch over a time period of a workpiece piercing sequence; comparing the characteristic to a threshold value; and responsive to determining that a calculated characteristic meets and/or exceeds the threshold value, ending the workpiece piercing sequence and beginning the cutting sequence and causing the plasma arc torch to move relative to the workpiece to form a cut.

A torch head for a liquid-cooled plasma arc torch is provided. The torch head includes a torch body and a torch insulator, coupled to the torch body, having a substantially non-conductive insulator body. The torch insulator includes (i) a first liquid coolant channel, disposed within the insulator body, configured to conduct a fluid flow from the torch head into a consumable cartridge along a first preexisting flow path, (ii) a first liquid return channel, disposed within the insulator body, configured to return at least a portion of the fluid flow from the cartridge to the torch head along the first preexisting flow path, and (iii) a gas channel, disposed within the insulator body, configured to conduct a first gas flow from the torch head to the cartridge along a second preexisting flow path. The first and second preexisting flow paths are fluidly isolated from each other.

A plasma processing system includes a torch having a consumable. A gas pressure regulator includes an input pressure sensor configured to sense an input pressure to the gas pressure regulator. A gas conduit supplies gas from the gas pressure regulator to the torch. A controller is operatively connected to the gas pressure regulator to receive an input pressure signal from the input pressure sensor and to provide a control signal to the gas pressure regulator to control operations of the gas pressure regulator and set an output pressure of the gas pressure regulator. The controller is configured to identify the consumable based on both of the input pressure to the gas pressure regulator and the control signal provided to the gas pressure regulator.

In some aspects, methods for preserving a usable life of a plasma arc electrode consumable installed in a plasma arc torch can include measuring a characteristic of an electrical signal being provided to the torch to generate a plasma arc between the torch and a workpiece to be processed; monitoring the characteristic during operation of the torch over a time period; comparing the characteristic to a threshold value; and, responsive to determining that a measured characteristic meets and/or exceeds the threshold value, initiating an arc extinguishing sequence to preserve the life of the electrode.

In some aspects, methods for controlling a pneumatic system in a plasma arc processing system can include: receiving, by a computing device, a command to begin a plasma processing operation; generating a valve command signal for a valve that includes an operational drive voltage of at least about 125% of a continuous duty cycle coil voltage rating of the valve to open the valve; and once open, adjusting the valve command signal to facilitate a steady state operation to: monitor a steady state operational duty cycle of the valve, the steady state operational duty cycle being determined by comparing the continuous duty cycle coil voltage rating of the valve to an actual operational drive voltage supplied to the valve, and control the operational drive voltage supplied to the valve to maintain a steady state operational duty cycle of the valve at less than about 60% during steady state operation.

Approaches herein provide a plasma arc torch including a tip surrounding an electrode, the electrode having a proximal end and a distal end, and a shield surrounding the tip, the shield including an exit orifice proximate the distal end of the electrode. The torch may further include a linear actuating device coupled to the electrode for actuating the electrode such that the distal end of the electrode moves axially relative to the tip and the exit orifice of the shield. In some approaches, the linear actuating device is operable to actuate the electrode along a central longitudinal axis extending through the tip. In some approaches, the linear actuating device may include one of: a micro linear drive motor, a micro linear stepper motor, a voice coil, a solenoid coil, and a magnetostrictive actuator. In some approaches, the electrode is actuated during a welding or cutting cycle of the torch.

A torch head for a liquid-cooled plasma arc torch is provided. The torch head includes a torch body and a torch insulator, coupled to the torch body, having a substantially non-conductive insulator body. The torch insulator includes (i) a first liquid coolant channel, disposed within the insulator body, configured to conduct a fluid flow from the torch head into a consumable cartridge along a first preexisting flow path, (ii) a first liquid return channel, disposed within the insulator body, configured to return at least a portion of the fluid flow from the cartridge to the torch head along the first preexisting flow path, and (iii) a gas channel, disposed within the insulator body, configured to conduct a first gas flow from the torch head to the cartridge along a second preexisting flow path. The first and second preexisting flow paths are fluidly isolated from each other.