Irregularly-shaped die and method for producing irregularly-shaped wire

Abstract

An irregularly-shaped diamond die is an irregularly-shaped die for producing an irregularly-shaped wire, wherein a processing hole having a bearing portion is provided, a first side and a second side that face each other are provided in a cross section of the bearing portion perpendicular to a wire drawing direction, and each of the first side and the second side has a shape that is convex toward a center side of the processing hole in the cross section.

1 . An irregularly-shaped die for producing an irregularly-shaped wire, wherein
 a processing hole having a bearing portion is provided,   a first side and a second side that face each other are provided in a bearing cross section of the bearing portion perpendicular to a wire drawing direction, and   each of the first side and the second side has a shape that is convex toward a center side of the processing hole in the bearing cross section.   
     
     
         2 . The irregularly-shaped die according to  claim 1 , wherein
 a maximum distance between the first side and the second side is more than 100% and equal to or less than 150% of a minimum distance.   
     
     
         3 . The irregularly-shaped die according to  claim 1 , wherein
 a reduction portion is provided upstream of the bearing portion in the wire drawing direction,   the first side and the second side are provided in a reduction cross section of the reduction portion perpendicular to the wire drawing direction and the bearing cross section,   a corner portion of the processing hole is provided at an end of each of the first side and the second side in the reduction cross section, and   an opening angle of reduction of the corner portion is different from an opening angle of reduction of each of the first side and the second side.   
     
     
         4 . The irregularly-shaped die according to  claim 3 , wherein
 the opening angle of reduction of the corner portion is greater than the opening angle of reduction of each of the first side and the second side.   
     
     
         5 . The irregularly-shaped die according to  claim 4 , wherein
 the opening angle of reduction of the corner portion becomes greater with increasing distance from the first side and the second side and toward a tip of the corner portion.   
     
     
         6 . A method for producing an irregularly-shaped wire, wherein
 a wire is processed using a first irregularly-shaped die, the irregularly-shaped die as recited in  claim 1 , and a second irregularly-shaped die in this order.   
     
     
         7 . A method for producing an irregularly-shaped wire, wherein
 a wire is processed using a first irregularly-shaped die, the irregularly-shaped die as recited in  claim 3 , and a second irregularly-shaped die in this order.