| 摘要 |
PURPOSE:To elevate the reliability and durability by preventing the electrochemical corrosion and gas leak of a temperature sensing section by crushing the tip of the thermo-sensitive part of a power element to form a semi-circular arc in the cross-section with the diameter thereof almost equal to the thermosensitive part and sealing up the crushed part by fusion. CONSTITUTION:The tip 2 of the thermosensitive part 1 of a power element formed by swaging and reducing the other end of a stainless steel pipe is crushed with a die 4 which has a concave 4a with a semi-circular arc cross-section almost equal in the diameter D3 to the diameter D1 of the thermosensitive part 1 and a die 5 which has a convex 5a with a semi-circular cross-section equal in the diameter D4 to D1-2t1 with the thickness t1 of the part 1. The crushed part undergoes an argon welding, a laser beam welding or the like to form a seal-up section 7 with the diameter D2 almost equal to the diameter D1. Thus, an element is obtained simply and at a low cost with a seal-up construction easy to mount a shell such as a boiler and excellent in the reliability and durability free from electric corrosion, leak of gas or the like. |
