| 摘要 |
PURPOSE:To form the joint part of superior pressure resistance and thrust resistance by fitting the connecting pipes into a socket built-in with sealing materials in the grooves in its inside circumferential direction then reducing the diameter of the pipes and further plastically deforming the portion within the reduced-diameter range continuously to an intermittent recess by the specified method. CONSTITUTION:Pipes 5, 5 are respectively fitted to the joint S which has a clearance C into which the connecting pipes 5, 5 readily fit, is formed with grooves 2 in the circumferential direction of the inside surface in the innermost part of the socket parts 1 on both sides and is built in with O-rings or the like in these. The pipes are then reduced of diameter by vertically split die press tools 7, 7' to pressure weld the range Z2 of the annular grooves to the state of being bitten to the outside wall surface of the pipe 5 to perfectly prevent the entry of fluid or the like into the fitting part. At the same time, the circumferential surface of the fixed zone Z3 within the diameter- reduced range Z1 is plastically deformed to polygonal shape or the deformed shape having recesses at a number of equally divided portions by the pressing pieces 7a, 7a' formed to the press tools 7, 7'. This makes the connection firm through cooperative action with the pressure welding of the sealing materials 3. It is more effectual to coat adhesive agents on the outside surfaces of the connected pipes. |
