METHOD FOR MANUFACTURING METAL CYLINDER MEMBERS OF ELECTRON TUBES AND METHOD FOR MANUFACTURING MAGNETRON ANODES

摘要

A method for manufacturing a metal cylinder of an electron tube comprises the steps of rolling a metal plate (26) into a cylinder (27), reduction-forming the cylinder (27), welding the seam (23) of the reduction-formed cylinder (27) by means of a high-energy beam, and compression-forming the resulting cylinder (27) in the axial direction while restricting the inner and outer peripheral surfaces thereof. The step of beam welding the seam (23) includes arranging a plurality of cylinders (27) to be subjected to the welding lengthwise, so that the adjacent ends of the cylinders (27) are in intimate contact with one another, whereby the respective seams (23) of the cylinders (27) extending in a straight line are subjected in succession to the beam welding. The power of the high-energy beam irradiated onto the seam (23) of each cylinder (27) is controlled so as to be higher in the initial stage of the application to each cylinder (27) and lower in the later stage. A method for manufacturing a magnetron anode comprises the steps of rolling a copper plate (26) into a cylinder (27), reduction-forming the cylinder (27), welding the seam (23) of the reduction-formed cylinder (27) by means of a high-energy beam, compression-forming the resulting cylinder (27) in the axial direction while restricting the inner and outer peripheral surfaces thereof, thereby completing an anode cylinder (21), and radially fixing a plurality of anode vanes (22) to the inside of the anode cylinder (21). The high-energy beam for welding is irradiated diagonally to the longitudinal plane of the seam (23).