| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of working a branch hole, in which a flange is easily formed on the branch hole formed on a metallic pipe. SOLUTION: A lower hole 8 is bored in the middle of the metallic pipe 1. Then, a pin 17 is inserted into the lower hole. After that, the pin 17 is brought into contact with the inside of the lower hole and moved in the forming direction of the hole while rotating the pin, so that the flange 4 as well as the branch hole 3 is formed. COPYRIGHT: (C)2009,JPO&INPIT
|
