| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To consistently form a locking projecting bar of the high quality on various pipe bodies irrespective of the diameter size of the pipe bodies and irrespective of the wall thickness of the pipe bodies when forming the locking projecting bar on an outer circumferential surface of a pipe end joint of a fluid feed pipe by the form rolling method. <P>SOLUTION: When forming a locking projecting bar on an outer circumferential surface of an end of a pipe body by the form rolling method by using an inner form rolling roll 5 located inside a pipe body to be worked, and an outer form rolling roll 6 having a forming annular groove located outside the pipe body, the locking projecting bar is formed while imparting the pressure in the axial direction of the pipe body to the pipe body. The flow of a pipe body material required for forming the locking projecting bar is sufficiently performed to consistently form the locking projecting bar having the uniform height and wall thickness. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT</p> |
