| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat fusion method for a pipe and joint made of thermoplastic resin, by which method, the pipe at the end of the joint hardly splits when a bending moment has been applied to the joint. SOLUTION: The end portion of the pipe 1 is joined with the joint 2 by the heat fusion method through providing a non-fusion zone B having a definite width at the inlet portion of the insertion port of the joint. As a result, a deflection angle at the boundary point c between the fusion zone A and the non-fusion zone B becomes zero when the bending moment M is applied to the joint. Therefore, a tensile stress at the boundary point c becomes zero, and the split of the pipe 1 at the point c does not occur. Further, because a clearance is produced between the joint 2 and the pipe 1 at the point d of the end of the joint 2, the pipe 1 is smoothly bent. As a result, the deflection angle and the tensile stress become smaller than those in the case that the pipe is fixed at the point d. Therefore, the split of the pipe 1 at the point d is hardly caused. COPYRIGHT: (C)2005,JPO&NCIPI |
