Automatic positioning on the joint line during electron beam welding in conditions of action of magnetic interference

Positioning on the joint line during the electron beam welding is a difficult scientific and technical problem to achieve the high quality of welded joints in the aerospace industry, shipbuilding and power engineering. The final solution of this problem is not found. This is caused by weak interference protection of sensors of the joint position directly in the welding process. Eelectron- beam welding is often followed by indignations in the form of the magnetic fields leading to a deviation of an electron beam from an optical axis of a gun. The collimated X-ray sensor is used to monitor the beam deflection from the optical axis of the electron beam gun. The X-ray sensor is placed on the electron beam gun. The collimation slit of X-ray sensor is aimed at the optical axis of the gun. The method of synchronous detection is used to process information from the X-ray sensor. The method of synchronous detection uses the technological scanning of electron beam across the joint line. The technological scanning allows to select the signals of the first and second harmonics of the scanning frequency of the electron beam across the joint line. The authors analyzed the impact of the gap width in the joint and the joint deflection from the optical axis of the gun on the output signal of the collimated X-ray sensor. The authors propose a two-circuit system for automatic positioning of the electron beam on the joint connection during the electron beam welding in conditions of action of magnetic interference. This system includes a circuit of joint tracking and circuit of compensation of magnetic fields. Two-circuit system uses a secondary-emission sensor to monitor the position of the joint. The proposed system is stable.