| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of forming groove in a pipe material, which increases durability of a core die, reduces the cost of equipment and facilitates groove pitch changing. <P>SOLUTION: The method of forming groove in the pipe material 10 forms a rectangular groove 10a and an inclined groove 10b in an outer peripheral surface of the pipe material 10. The first core die 1 is inserted through one end port 10c in the pipe material 10 and the second core die 2 is inserted through the other port 10d in the pipe material 10. The rectangular groove 10a is formed by punching the pipe material 10 on a part corresponding to a space S set between facing vertical faces 1a, 2a of the first core die 1 and the second core die 2 by a punch 14 for rectangular groove. The inclined groove 10b is formed by punching the pipe material 10 on a part corresponding to the vertical face 2a of the second core die 2 at a position corresponding to the groove pitch P by a punch 15 for inclined groove. <P>COPYRIGHT: (C)2013,JPO&INPIT |
