| 摘要 |
PURPOSE:To prevent a texture surface from wearing and tearing quickly by the use of a specified stainless steel in the parent material of a mold, and creating a texture surface through an electric discharge on the surface thereof. CONSTITUTION:A cavity is defined by a stationary mold 11 and a movable mold 12 during mold clamping. The stationary mold 11 forms the outer surface of a case half, and the movable mold 12 forms the inner surface thereof. The stationary mold 11 forms a label surface and sculptured surface 14, a recession for incorporating the shutter, and a sculptured surface corresponding to the opening window, and further forms a texture surface 15 by electric discharge at a desired position in the sculptured surface of the label surface or the like. In this process, the surface rigidity of the texture surface 15 is so high that wear and tear of the texture surface 15 can be prevented during the period of molding. Furthermore, as the parent material of the stationary mold 11, stainless steel SUS 440 is employed, and when the surface rigidity of the texture surface 15 is made HRC=60 or more, wear and tear can be prevented positively in the texture surface 15. |
