| 摘要 |
PURPOSE:To improve fusion resistance, current interrupting property, and current chopping value by forming an electrode material of respective specified amounts of copper, chromium and bismuth. CONSTITUTION:Lead bars 11, 12, electrodes 13, 14, a shield 15, insulating cylinders 16, 17, metal end plates 18, 19 and a bellows 20 are provided. The material of the electrodes 13, 14 is formed of 20-98wt.% of copper, 2-80wt.% of chromium, and 0.1-1wt.% of bismuth. In this case, copper and bismuth are welded and immersed into the void part of chromium powder, and the immersing work of copper and bismuth to chromium is desirably performed under non- acidifying atmosphere and with degasing. The bismuth lowers the mechanical strength of an electrode contact part to make the electric contact part easy to deform, suppressing an increase in contact resistance value after current interruption. Thus, fusion resistance, current interrupting performance and current chopping value can be improved. |
