| 摘要 |
PURPOSE:To reduce the number of manufacturing processes and to eliminate waste of material by pressing and forming a thermoplastic resin lump as a diaphragm in a gap between upper and lower metallic dies forming a gap of the diaphragm shape. CONSTITUTION:A lower metallic die 1 having a conical projection 11 at the center in matching with the shape of diaphragm and provided with annular recess 12 at the circumference in matching with the edge shape, is prepared and an edge 20 having U-shaped cross section is arranged in the annular recess groove 12. A prescribed amount of the thermoplastic resin lump 3 in the plastic state by heating is placed on a flat face at the center top of the conical projection 11. Further, an annular side metal die 4 having an annular projection stripe 42 in matching with the edge 20 contained in the recess groove 12 is prepared. In pressing down an upper metallic die 5 of cylindrical shape onto the lower metallic die 1, the resin lump 3 in plastic state between the metallic dies is pressed. Thus, the formed thermoplastic resin 31 is filled in the gap. The resin 31 is welded thermally to the inner circumference piece 21 of the edge 20. |
