Patent ID: 6875948

Claim:
Method for controlling the butt welding process, by flash welding, of two metallic parts arranged after one another along a longitudinal running axis, in a welding machine of the type comprising two pairs of clamping dies mounted respectively on a fixed frame and on a mobile frame moveable with respect to the fixed frame, electric welding means comprising an electric power supply source with two poles connected respectively to both pairs of clamping dies, means for controlling the clamping of both pairs of dies, respectively close to a rear end in the running direction, of a first part and close to a front end of a second part, and means for controlling the longitudinal travel of the mobile frame with respect to the fixed frame, for contacting said rear and front ends of both parts and the flow of an electric current with a welding voltage and intensity, a method wherein the travel of the mobile frame is controlled automatically, at least during the flash welding process, wherein the value of a set of electric parameters including at least the voltage and the intensity of the welding current and, the relative position of the mobile frame with respect to the fixed frame are determined at any moment and the travel of the mobile frame, is controlled in position from at least one of the values thus determined, in order to control the relative position and the closing-in speed v(t) of the ends of both parts according to the progress of the welding process, during at least a portion thereof.