| 摘要 |
PURPOSE:To form a continuous reversal natural film by connecting not machined connecting faces between the internal bottom face of a cavity gouged out in the raw material of a metallic mold and reversal natural patterns formed on each inside face of the cavity by an electric discharge machining electrode, by means of corrosion- or engraving machining. CONSTITUTION:In accordance with an internal bottom face 2a, and inside faces 2b, 2c of a specified-shaped cavity 1 gouged out in a metallic mold-raw material electrode-base segments 3a, 3b, 3c, 3d are prepared in divided form, the internal bottom face and each inside faces of the cavity 1 are separately electro- discharge machined by the electrodes 5a, 5b, 5c, 5d joined with the metallic sheets 4 provided with the same convex and concave patterns as the natural pattern on the surfaces of respective electrode-base segments, and the reversal natural patterns 6 are formed on respective faces. On the not machined connecting faces 7 remained in the corner parts of the cavity 1 between respective patterns, continuous patterns 6 of reversal natural patterns connecting respective reversal natural patterns to each other are formd by corrosion- or engraving machining. |
