Sheet-material forming device and method

Abstract

The present invention relates to a sheet-material forming device and method which can be easily changed in response to modifications and changes in a target shape and which can implement forming even curved surfaces with edges or localized small radiuses of curvature.

1 - 12 . (canceled) 
     
     
         13 . A sheet-material forming apparatus comprising:
 upper and lower variable molds configured to be movable up and down with a sheet material to be formed interposed between the variable molds,   wherein the upper and lower variable molds are constructed by combining a plurality of mold blocks,   wherein the plurality of mold blocks includes:   at least one forming punch block having an array of punches for forming curved surface with various radiuses of curvature; and   at least one integral forming block having a part for forming curved surface with locally small radiuses of curvature and/or edges.   
     
     
         14 . The sheet-material forming apparatus according to  claim 13 , wherein:
 the forming punch block comprises first, second, third, . . . , N th  forming punch blocks, in each of which the punches having cross-section of different sizes are arranged, and   each of the forming punch blocks includes a support member for supporting the corresponding punches and for being combined with a neighboring mold block.   
     
     
         15 . The sheet-material forming apparatus according to  claim 13 , wherein each of the punches of the forming punch block is adjustable in the height. 
     
     
         16 . The sheet-material forming apparatus according to  claim 13 , wherein each of the punches of the forming punch block has a circular cross-section and a rounded end. 
     
     
         17 . The sheet-material forming apparatus according to  claim 13 , wherein each of the punches of the forming punch block has a polygon cross-section and a rounded end. 
     
     
         18 . The sheet-material forming apparatus according to  claim 13 , wherein the forming punch block further comprise elastic pads interposed between the punches and the sheet material to be formed for forming smooth curved surface. 
     
     
         19 . The sheet-material forming apparatus according to  claim 13 , wherein:
 the integral forming block comprises at least one edge block for forming curved surface with an edge and/or at least one small-radius-of-curvature block for forming curved surface with a small local radius of curvature, and   the edge block and the small-radius-of-curvature block comprise a respective support member for supporting the block and for being combined with a neighboring mold block.   
     
     
         20 . The sheet-material forming apparatus according to  claim 13 , further comprising:
 a fixing die for the plurality of mold blocks combined based on a target shape of the sheet material to be formed; and   a punch height adjustment module for adjusting heights of the punches to produce a forming surface according to the target shape.   
     
     
         21 . A sheet-material forming method using the sheet-material forming apparatus according to  claim 13 , comprising the steps of:
 a) modeling a target shape;   b) selecting mold blocks corresponding to the shape and the curvature of surface resulting from the modeling of the step a), combining the selected mold blocks, and adjusting heights of punches, in order to construct a forming surface corresponding to the target shape;   c) correcting the constructed forming surface; and   d) finally forming the sheet material.   
     
     
         22 . The sheet-material forming method according to  claim 21 , wherein the step c) comprises the steps of:
 forming a trial product;   measuring error of the shape of trial product and determining whether the measured error falls within a tolerance; and   reconstructing a corrected forming surface, if the measured error of the trial product is not within the tolerance,   wherein the step of reconstructing a corrected forming surface is performed repeatedly until the trial product satisfies the tolerance.   
     
     
         23 . The sheet-material forming method according to  claim 21 , wherein the step c) comprises the steps of:
 analyzing the constructed forming surface;   evaluating an amount of elastic recovery of the sheet material through elastic recovery analysis;   predicting the shape of a trial product based on the evaluation and determining whether the error of the trial product falls within a tolerance; and   reconstructing a corrected forming surface, if the error of the trial product is not within the tolerance,   wherein the step of reconstructing a corrected forming surface is performed repeatedly until the trial product satisfies the tolerance.