NEGATIVE ELECTRODE PART FOR MAGNETRON, AND MAGNETRON DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To improve welding strength at a welding portion by welding a groove-shaped recessed part formed in an end hat for magnetron with a tip of a negative electrode lead supporting the end hat on a butting surface. SOLUTION: A groove-shaped recessed part 18 with a given size provided on the lower surface of a lower end hat 10 having a substantially recessed-type cap-shaped cross section and a through hole in a central part is positioned so that the center of the width of the groove substantially matches to the center of a second negative electrode lead 12. The groove-shaped recessed part 18 is matched to the tip surface of the second negative electrode lead 12, and is buttwelded to provide a second negative electrode structure. At this time, a melted portion intrudes into the groove-shaped recessed part 18 in a wedge shape and solidifies, and essential welding area increases. The groove-shaped recessed part 18 is formed with a cutting process during powder molding or after a press machining or sintering after pre-sintering, when the lower end hat 10 is manufactured by sintering a pressurized compact of molybdeum powders. For the positioning of symmetrical lower end hat 10 and the second negative electrode lead 12, ring shape is more suitable than longitudinal shape.