Press die, drawing method, and pressed product

Abstract

A press die for molding an edge wall at a peripheral edge of a workpiece includes a die convexly formed along a shape of one surface of the edge wall, a punch formed with a concave portion along the other surface of the edge wall, and a stripper for holding the workpiece with the die therebetween, wherein a clearance between the die and the punch is in a range of not less than 70% and not more than 95% of a thickness of the workpiece before forming.

1 . A press die for forming an edge wall at a peripheral edge of a workpiece, the press die comprising:
 a die formed convexly along a shape of one face of the edge wall;   a punch formed concavely along a shape of the other face of the edge wall; and   a stripper configured to sandwich the workpiece together with the die,   wherein a clearance between the die and the punch is in a range of not less than 70% and not more than 95% of a thickness of the workpiece before forming.   
   
   
       2 . The press die according to  claim 1 , wherein a convex portion width of the die is in a range of not less than 100% and not more than 400% of the thickness of the workpiece before forming and a height of the die is formed in a range of not less than 5% and not more than 20% of the thickness of the workpiece before forming. 
   
   
       3 . The press die according to  claim 2 , wherein the die comprises the convex portions at opposed positions. 
   
   
       4 . A drawing method comprising the step of:
 bending a peripheral edge of a workpiece sandwiched by a die and a stripper while the peripheral edge being drawn by applying a pressing force through a punch,   wherein a clearance between the die and the punch is in a range of not less than 70% and not more than 95% of a thickness of the workpiece before forming.   
   
   
       5 . A pressed product comprising:
 an edge wall formed by dispensing drawing at a peripheral edge of a workpiece,   wherein a thickness of the peripheral edge is in a range of not less than 72% and not more than 97% of a thickness of the workpiece before forming.   
   
   
       6 . A pressed product according to  claim 5 , wherein a maximum width from a center to an edge is in a range of not less than 25 times and not more than 700 times of the thickness of the workpiece before forming. 
   
   
       7 . The pressed product according to  claim 5 , wherein a height of the edge wall is in a range of not less than three times and not more than 25 times of the thickness of the workpiece before forming. 
   
   
       8 . The pressed product according to  claim 6 , wherein a height of the edge wall is in a range of not less than three times and not more than 25 times of the thickness of the workpiece before forming. 
   
   
       9 . The pressed product according to  claim 5 , wherein the thickness of the workpiece before forming is not more than 0.5 mm. 
   
   
       10 . The pressed product according to  claim 6 , wherein the thickness of the workpiece before forming is not more than 0.5 mm. 
   
   
       11 . The pressed product according to  claim 7 , wherein the thickness of the workpiece before forming is not more than 0.5 mm. 
   
   
       12 . The pressed product according to  claim 8 , wherein the thickness of the workpiece before forming is not more than 0.5 mm. 
   
   
       13 . The pressed product according to  claim 5 , wherein the workpiece is any one of stainless steel SUS (Special Use Stainless) 304-SP (Steel Plate), aluminum, and stainless steel SUS 304-CSP (Cold rolled stainless steel for Springs). 
   
   
       14 . The pressed product according to  claim 6 , wherein the workpiece is any one of stainless steel SUS304-SP, aluminum, and stainless steel SUS 304-CSP. 
   
   
       15 . The pressed product according to  claim 7 , wherein the workpiece is any one of stainless steel SUS304-SP, aluminum, and stainless steel SUS 304-CSP. 
   
   
       16 . The pressed product according to  claim 8 , wherein the workpiece is any one of stainless steel SUS304-SP, aluminum, and stainless steel SUS 304-CSP. 
   
   
       17 . The pressed product according to  claim 9 , wherein the workpiece is any one of stainless steel SUS304-SP, aluminum, and stainless steel SUS 304-CSP. 
   
   
       18 . The pressed product according to  claim 10 , wherein the workpiece is any one of stainless steel SUS304-SP, aluminum, and stainless steel SUS 304-CSP. 
   
   
       19 . The pressed product according to  claim 11 , wherein the workpiece is any one of stainless steel SUS304-SP, aluminum, and stainless steel SUS 304-CSP.