| 摘要 |
PURPOSE:To prevent the current quality at the time of welding from increasing and to suppress excess heat generation so as to suppress the stress on a stem at the time of welding by fitting the outside diameters of a holder and the stem via a spacer consisting of an insulator. CONSTITUTION:After the stem 2 is fitted to the holder 1 via the annular spacer 8a consisting of the insulator, the stem is fixed by resistance welding to the holder 1. The spacer 8a consisting of the insulator is a rigid body, for example, ceramics, etc., having such a size as to have below about some tens micron spacings respectively to the outside diameter of the stem 2 and the diameter of the hole for fitting possessed by the holder 1. Then, the spacer plays the role of mechanically determining the position of fixing the stem 2 to the holder 1 and simultaneously decreasing the area of the contact to be welded at the time of resistance welding of the holder 1 and the stem 2 and preventing the flow of a current by the contact of the flank 9b of the stem and the holder 1. |
