| 摘要 |
PURPOSE:To hold surely a brazing material to a base material by punching a through-hole to the base material, press-fitting and fixing the brazing material in the through-hole and caulking the wall of the hole before and after the brazing material thereby detaining and fixing the brazing material into the through-hole. CONSTITUTION:A square hole consisting of a large-diameter hole 2a and a small-diameter hole 2b is punched to a base material 1 by a stepped punch. A silver brazing material 3 is cut and press-fitted into said hole with the hole 2a as a die having a cutting edge and is held in the step part at the bottom of the hole 2a. A punch is then pushed into the hole 2a to expand the hole and a tonque piece 4 is caulked by the end face of the punch, by which the brazing material is caulked. A stepped punch is pushed into the hole 2a and the material 3 is pressed by the tip thereof to form the aperture of the piece 4 into a square hole; at the same time, the aperture is narrowed by the tonque piece 5 detaining the surface on the outside of the material 3, by which the 2nd stage of caulking is performed. The material 3 is thus grasped by the pieces 4, 5, by which said material is surely fixed and held. |
