| 摘要 |
PURPOSE:To weld satisfactorily a small-diameter pipe to a tubular structure in an easy position by providing a projection for forming a clearance to permit manipulation of an electrode to the horizontal part at the axial center of the end face of the horizontal small-diameter pipe, fitting a backing plate provided with a projection into the pipe hole, executing flat welding then subjecting the remaining half to flat welding after rolling-over the entire part and removing the backing plate. CONSTITUTION:The projection 4 for forming the clearance to permit manipulation of a welding electrode is provided to the horizontal part at the axial center of the end face 3 of the horizontal small-diameter tube 1 and the backing plate 5 having the similar horizontal projection 5a is fitted into the hole of the tube 1. The backing plate is also fitted into the hole of the tubular structure 8 when necessary and the tube 1 is pressed into the hole of the structure 8. If the flat welding is executed in this state, the side part is also received by the projecting part 4 and the welding is satisfactorily executed without the inflow of the molten metal into the pipe. The remaining half is subjected to the flat welding after the entire part is rolled-down 180 deg. and the backing plate is removed. The tube circumference is welded without defects by the ordinary flat welding using the small projection, by which the automatic welding is made satisfactory and easy. |
