Method of manufacturing vehicle pillar and press forming die

Abstract

A method of manufacturing a vehicle pillar includes: a blanking for obtaining a work piece by cutting a material; a drawing for obtaining an intermediate product by forming the work piece, using an upper die and a lower die; and a trimming for removing an unnecessary portion of the intermediate product. In the drawing, both ends of the work piece in a longer side direction are clamped between pressing pads and a punch. Then, in the drawing, both ends of the work piece in a shorter side direction are clamped between blank holders and a die. In the drawing, a center portion of the work piece is clamped between the die and the punch to form the work piece, while the clamping performed by the pressing pads and the punch, and the clamping performed by the blank holders and the die are maintained.

1 .- 3 . (canceled) 
     
     
         4 . A press forming die that is used to press form a work piece, and is used for manufacturing a vehicle pillar including: an upper pillar portion that is coupled to a roof rail, when the vehicle pillar is assembled to a vehicle body; a lower pillar portion that is coupled to a side sill, when the vehicle pillar is assembled to the vehicle body; and a center pillar portion that connects the upper pillar portion and the lower pillar portion, and extends in a height direction of the vehicle body, the press forming die comprising:
 an upper die that includes a die and a pair of pressing pads; and   a lower die that includes a punch and a pair of blank holders, wherein   the upper die and the lower die are configured such that both ends of the work piece in a longer side direction are clamped between the pressing pads and the punch, before a center portion of the work piece is clamped between the die and the punch to form the work piece.   
     
     
         5 . The press forming die according to  claim 4 , wherein
 one of the ends of the work piece in the longer side direction, that is clamped between the pressing pads and the punch is a part of a portion to be formed as the upper pillar portion of the vehicle pillar, and   the other of the ends of the work piece in the longer side direction, that is clamped between the pressing pads and the punch is a part of a portion to be formed as the lower pillar portion of the vehicle pillar.   
     
     
         6 . The press forming die according to  claim 4 , wherein
 either one of the ends of the work piece disposed on the lower die in the longer side direction, includes an inclined surface that is inclined downward or upward relative to a horizontal direction,   clamping surfaces for clamping the inclined surface are formed on the pressing pads and the punch that clamp the inclined surface, and   opposing surfaces are formed at outer positions in the horizontal direction of the clamping surfaces formed on the pressing pads and the punch that clamp the inclined surface, the opposing surfaces being inclined in an opposite direction to the inclined surface relative to the horizontal direction.