| 摘要 |
PURPOSE:To prevent deformation produced in the pipe itself by a method wherein the cooling fin is wound around the pipe and secured thereto without applying a grooving and a calking processes to the pipe. CONSTITUTION:The cooling fin 11 is formed by rolling and is wound around a positve pole cylinder 10 and the cooling fin 11 is pinched with a rolling roll 13 and a spindle roll 14. In that condition, neighboring fins 11a, 11b are secured each other by using a cutting and bending tool 15. The blade tips 16a, 18a of the cutting and bending tool 15 pinches the outer peripheral part of the neighboring fins 11a, 11b simultaneously under a condition that they are being opened, then, the blade tips 16a, 18a are closed. According to this operation, notches are made simultaneously at two places on the outer peripheral part of the fins 11a, 11b and both of the notches are bent in zig zag and are engaged each other to form the processed part 19 of the cutting and bending, thereby securing the fins 11a, 11b. |
