| 摘要 |
PURPOSE:To prevent a shrinkage of sheets nearby the border of a welded part and a non-welded part so as to prevent a breakage of a pocket part by heating and welding only parts to be welded of a protector with a heated metal mold while cooling the protector except for those parts to be welded. CONSTITUTION:In process A, a release sheet 32a is necessarily placed upon a lower cooling metal mold 1 and a sheet 31a is placed thereupon. The total periphery of a tube 11, the total lower face of the lower sheet 31a and the total upper face of the upper sheet 31a are brought into contact with the upper and lower cooling metal molds 3 and 1 through release sheets 32a and 32b, so that a pocket part 14 is formed. On the other hand, parts of the upper sheet 31b slightly apart from the tube 11, i.e., the positions which are to be welded parts 13, are brought into contact with press faces 27 of a heated metal mold 4. In process B of this invention, therefore, parts, which are not welded, are maintained in a cooled state without being heated and the welded parts 13 alone are heated and welded. A protector 12 is obtained by trimming the outer peripheries of the welded parts with an ultrasonic cutter and an NC machine. |
