| 摘要 |
PURPOSE:To generate simultaneously a high layer expanding force and a large temp. difference and to improve a fitting force by exerting further a pipe expanding pressure on an inside pipe in the short time when there is a temp. difference of double-pipe formed by giving the temp. difference between the inside and outside pipes and superposing the two pipes. CONSTITUTION:A pipe expanding force is exerted in the inside pipe of double- pipe formed by superposing the inside and outside pipes in the state of having a temp. difference to increase the diameter and to deform plastically the inside pipe, thereby fitting tightly the inside pipe to the outside pipe. The pressure is further exerted thereon in the extremely short time when the temp. difference between the inside and outside pipes is maintained so that the inside and outside pipes are simultaneously expanded. The degree of fitting is improved by the elastic shrinkage and thermal shrinkage of the outside pipe. |
