| 摘要 |
PURPOSE:To obtain a branch pipe having no weld lines in the branch part by clamping a base pipe bored with a prepared hole and heating the pipe with split type coils and saddle type coil then rising a cross head. CONSTITUTION:The prepared hole 1a is bored to the prescribed position of the base pipe 1 and thereafter the pipe is fixed to a pair of clamps 4. The cross head 16 which moves upward and downward is attached to posts 17 fixed onto a lower bed 18 and a rod 6 for drawing a burring punch 5 inserted into the pipe 1 is fixed to the bottom surface thereof. Both hydraulic cylinders 13 are driven by the oil pressure generated in a press operating device 12 and introduced therein through pipings 14 to move upward and downward the cross head 16. The saddle type coil 8 which is so formed as to maintain the uniform spacing from the pipe 1 over the entire circumference is provided near the outside circumferential part of the split type coils 7 and is connected to a high- frequency power source 11 like the coils 7.
|
