| 摘要 |
PURPOSE:To reduce a residual stress generating in a joint, by heating an outside member of the 1st pipe to insert the 2nd pipe into it and expanding inner parts after cooling, in joining both pipes together by inserting the 2nd pipe between the 1st pipe and a ring and expanding the inner parts. CONSTITUTION:In joining metallic pipes together, for instance, in joining a pressure pipe 1 to a lower extended pipe 2, a flared part 8 of the pipe 1 is obtained by flaring work, and an internal diam. of a part of the pipe 2, to be in contact with the part 8, is made smaller than an outer diam. of the pipe 1 by machining the inside of the pipe 2. Next, after screw-joining the pipe 2 and an inner ring 3, the pipe 2 of an outside member is heated by a heating coil 6. The heating is stopped when the inner diam. of pipe 2 becomes larger by thermal expansion, and the flared part 8 of the pipe 1 is inserted, then the pipes 1 and 2 are joined together by roll-joint expanding after cooling the pipe 2, thus the residual stress in the joint is reduced. |
