| 摘要 |
PURPOSE:To enable a value of preload which is applied to a pressure element after welding to be consistent by reducing influence of welding distortion. CONSTITUTION:A diaphragm 2 is placed on a pedestal 1 so that a pressure element 5 which is provided on the pedestal 1 is covered and pressure can be transmitted to the pressure element 5. Also, both of them 1 and 2 are supported by tools 3 and 4. Then, while a load P is applied in an axis-line direction of the diaphragm 2, the diaphragm 2 and the pedestal 1 are spot welded at a plurality of positions at a spot welding position Y2 which is at an upper side from a lower edge of the diaphragm 2. After that, the diaphragm 2 and the pedestal 1 are seam-welded at a seal welding position Y1 and an entire periphery of the lower edge of the diaphragms 2, thus enabling welding distortion due to seam welding where heat input is relatively large to be absorbed between the seam welding position Y1 and the spot welding position Y2 and a ratio of seam welding distortion occupied at the preload to be small. |
