Welding torch

A welding torch using a non-consumable welding electrode comprising:

• an inner tube enclosed by an outer tube;
• and
• a clamping device for clamping the non-consumable welding electrode, the clamping device including;
• a clamping heat sink;
• and
• an electrode holder having a receiving chamber extending in a longitudinal direction of the electrode holder for receiving the welding electrode, the receiving chamber, at a forward end of the electrode holder, defining a narrowed clamping region that widens into said receiving chamber, wherein the electrode holder has at said forward end a conical end portion which widens conically towards the forward end and is configured and arranged to be compressed by said clamping heat sink for holding the welding electrode,
• wherein the clamping heat sink in a clamped state of the clamping device is pushed mechanically against a mantle surface of the conical end portion of the electrode holder, so that in the clamped state said forward end of said electrode defines a large-surface cooling end face for cooling the welding electrode,
• wherein the clamping heat sink of the clamping device is configured for cooling a free electrode end of the welding electrode by a cooling fluid, the clamping heat sink defining a fluid chamber through which the cooling fluid flows and which in said clamped state of the clamping device encloses at least a portion of the conical end portion of the electrode holder for cooling the welding electrode inserted therein, and
• wherein a delivery line is provided between the inner tube and the outer tube to deliver the cooling fluid to said clamping heat sink, and a discharge line is provided between the inner tube and the outer tube for discharging cooling fluid.