Press die apparatus

Abstract

A press die apparatus includes a die and a backing plate. The die includes die holes into which punches are respectively inserted and withdrawn and first partition walls, each separating adjacent ones of the die holes from each other. The backing plate is adjacent to the die to support the die. The die includes die hole groups. The backing plate includes backing holes respectively connected to the die hole groups and a second partition wall, separating adjacent ones of the backing holes from each other. The second partition wall has a widened section that increases in width, continuously or in a stepwise manner, as the widened section extends away from the die. A maximum width of the widened section is greater than a width of the first partition wall.

What is claimed is: 
     
         1 . A press die apparatus, comprising:
 a die including:
 die holes into which punches are respectively inserted and withdrawn, the punches being configured to punch out a workpiece; and 
 first partition walls, each separating adjacent ones of the die holes from each other; and 
   a backing plate that is adjacent to the die to support the die, wherein   the die includes die hole groups, each including the die holes that are adjacent to each other,   the backing plate includes:
 backing holes respectively connected to the die hole groups; and 
 a second partition wall, separating adjacent ones of the backing holes from each other, 
   the second partition wall has a widened section that increases in width continuously or in a stepwise manner, as the widened section extends away from the die, and   a maximum width of the widened section is greater than a width of the first partition wall.   
     
     
         2 . The press die apparatus according to  claim 1 , wherein
 a portion of an inner surface of each of the backing holes that defines the widened section has an inclined surface, the inclined surface being sloped to be positioned further inside the backing hole as the inclined surface extends away from the die.   
     
     
         3 . The press die apparatus according to  claim 2 , wherein
 an end of the widened section where the die is located includes an edge formed by continuously connecting the inclined surfaces of adjacent ones of the backing holes to each other.   
     
     
         4 . The press die apparatus according to  claim 1 , further comprising a die holder that is adjacent to the backing plate to support the backing plate, wherein
 the die holder includes:
 holder holes respectively connected to the backing holes; and 
 a third partition wall, separating adjacent ones of the holder holes from each other, and 
   the third partition wall has a larger width than the first partition wall.   
     
     
         5 . The press die apparatus according to  claim 1 , wherein
 the die holes are arranged in an annular pattern.