Formation Tool for a Punching Machine

Abstract

A formation tool is used for deforming sheet metal on punching machines. The formation tool has an upper or top die tool and a lower or bottom die tool. Toward the top die, there is an upper mold insert movable relative to a holding-down device, and toward the bottom die, a lower mold insert movable relative to a stripper plate. The deformation of the metal sheet is effected upward with respect to a punching stroke plane. The formation tool has a lifting device for aiding in lifting the lower mold insert from an initial position which is at or below the punch stroke plane before a deforming operation, to a level above the punching stroke plane.

1 . A formation tool for sheet metal deformation on a punching machine, said die tool comprising:
 an upper top die tool;   a lower bottom die tool;   a holding-down device;   a stripper plate;   an upper mold insert being movable relative to the holding-down device, and cooperating with a lower mold insert, movable toward the bottom die relative to the stripper plate, to deform a metal sheet upward relative to a punching stroke plane; and   a lifting device for aiding in lifting the lower mold insert from an initial position which is at or below the punch stroke plane before a deforming operation, to a level above the punching stroke plane.   
   
   
       2 . The formation tool of  claim 1 , wherein an upper edge of the stripper plate, toward the bottom die, is located at the level of the punching stroke plane. 
   
   
       3 . The formation tool of  claim 1 , wherein the lifting device comprises a lifting element, disposed in a workbench, and a final control element disposed on the lower end of the lifting element. 
   
   
       4 . The formation tool of  claim 3 , wherein the lifting element has a tubular body. 
   
   
       5 . The formation tool of  claim 4 , wherein the tubular body has at least one lateral opening in a lower portion of the tubular body. 
   
   
       6 . The formation tool of  claim 5 , wherein the tubular body has two diametrically opposed openings in a lower portion of the tubular body. 
   
   
       7 . The formation tool of  claim 4 , wherein the final control element has a piston, which engages the lower end of the tubular body. 
   
   
       8 . The formation tool of  claim 7 , wherein the piston has a cylindrical protrusion, whose outer diameter is essentially equal to the inside diameter of the tubular body. 
   
   
       9 . The formation tool of  claim 8 , wherein the cylindrical protrusion is embodied in gable form on its face end, and the lower sides are located at the level of the lower edges of the two lateral openings, and the apex of the gable forms a protrusion, between the two openings, that divides the tubular body.