Shaping method and apparatus of thin metal sheet

Abstract

The invention provides a method and an apparatus capable of accurately shaping, within a short time, cubic products such as trial products for press molding for mass production without limitation of a molding shape. While edge portions of a blank are clamped, a mold punch having a molding shape is pushed from a sheet thickness direction to conduct rough forming. While the mold punch is kept pushed, shaping is conducted by use of a rod-like tool from an opposite side to the mold punch sandwiching the sheet thickness.

1 . A shaping method of a thin metal sheet comprising the steps of: 
 clamping edge portions of a thin metal sheet;    pushing under this state a mold punch finished to a product shape from below a sheet thickness direction;    conducting forming to shape a rough forming body having a top portion and side portions; and    finishing said rough forming body to a product shape by use of a tool capable of moving three-dimensionally with said mold punch as a mold surface from an opposite side to said mold punch sandwiching the sheet thickness while said mold punch is kept under a pushed state.    
     
     
         2 . A shaping method of a thin metal sheet according to  claim 1 , wherein said step of finishing to the product shape is carried out by using a rod-like tool and causing said rough forming body to undergo local plastic deformation.  
     
     
         3 . A shaping method of a thin metal sheet according to  claim 1 , wherein said step of finishing to the product shape is carried out in two stages of using an elastic tool and pushing said elastic tool to said mold punch from an opposite side to said mold punch while sandwiching the sheet thickness to cause local compression molding, and shaping said rough forming body to a finish shape by use of a rod-like tool.  
     
     
         4 . A molding apparatus of a thin metal sheet comprising: 
 a bed equipped with a mounting frame;    a plurality of wrinkle support devices arranged on said bed with intervals among them and clamping edge portions of a thin metal sheet in a sheet thickness direction;    a mold punch arranged inside a recess chamber which is formed in said bed more inward than said wrinkle support devices;    a mold punch elevation device for pushing said mold punch into said thin metal sheet supported by said wrinkle support devices;    a secondary molding device fitted to said mounting frame movably in three-axis directions; and    a tool fitted to said secondary molding device for conducting shaping of a rough forming body shaped by said mold punch in cooperation with said mold punch.    
     
     
         5 . A molding apparatus of a thin metal sheet according to  claim 4 , wherein said tool is two kinds of tools, that is, a local compression molding tool having a fitting portion and an elastomer, and a rod-like hard tool, the tools being removably fitted to a tool holder of said secondary molding device.