Press-forming method and method of manufacturing press-formed product

Abstract

A press-forming method includes: forming a blank having a concave shape corresponding to a curve of a concave curved portion of a target shape; press-forming the formed blank into a press-formed product having an intermediate shape having a top portion, a vertical wall portion continuous from the top portion, a flange portion continuous from the vertical wall portion, a concave curved portion curved in a concave shape in a top view, and a cutout portion located at a part of the flange portion and the vertical wall portion or at a part of the flange portion, the vertical wall portion, and the top portion in a central portion of the curve of the concave curved portion; and press-forming the press-formed product having the intermediate shape into the target shape. The press-forming is performed such that a part of the concave shape provided in the blank becomes the cutout portion.

1 . A press-forming method of press-forming a press-formed product into a target shape, the target shape including a top portion, a vertical wall portion continuous from the top portion, a flange portion continuous from the vertical wall portion, and a concave curved portion curved in a concave shape in a top view, the press-forming method comprising:
 a blank forming step of forming a blank provided with a concave shape corresponding to a curve of the concave curved portion of the target shape;   an intermediate shape forming step of press-forming the formed blank into a press-formed product having an intermediate shape, the intermediate shape having a top portion, a vertical wall portion continuous from the top portion, a flange portion continuous from the vertical wall portion, a concave curved portion curved in a concave shape in a top view, and a cutout portion located at a part of the flange portion and the vertical wall portion or at a part of the flange portion, the vertical wall portion, and the top portion in a central portion of the curve of the concave curved portion; and   a target shape forming step of press-forming the press-formed product having the intermediate shape into the target shape,   wherein the press-forming is performed in the intermediate shape forming step such that a part of the concave shape provided in the blank becomes the cutout portion.   
     
     
         2 . A press-forming method of press-forming a press-formed product into a target shape, the target shape including a top portion, a vertical wall portion continuous from the top portion, and a concave curved portion curved in a concave shape in a top view, the press-forming method comprising:
 a blank forming step of forming a blank provided with a concave shape corresponding to a curve of the concave curved portion;   an intermediate shape forming step of press-forming the formed blank into a press-formed product having an intermediate shape, the intermediate shape including a top portion, a vertical wall portion continuous from the top portion, a concave curved portion curved in a concave shape in a top view, and a cutout portion located at a part of the vertical wall portion and the top portion in a central portion of the curve of the concave curved portion; and   a target shape forming step of press-forming the press-formed product having the intermediate shape into the target shape,   wherein press-forming is performed in the intermediate shape forming step such that a part of the concave shape provided in the blank becomes the cutout portion.   
     
     
         3 . The press-forming method according to  claim 1 , wherein, in the intermediate shape forming step, a radius of curvature R E  at an end portion of the curve of the concave curved portion having the intermediate shape is set to be larger than a radius of curvature R 0  at the concave curved portion having the target shape. 
     
     
         4 . A method of manufacturing a press-formed product having a target shape, the target shape including a top portion, a vertical wall portion continuous from the top portion, a flange portion continuous from the vertical wall portion, and a concave curved portion curved in a concave shape in a top view, the method comprising:
 performing press-forming method according to  claim 1 .   
     
     
         5 . A method of manufacturing a press-formed product having a target shape, the target shape including a top portion, a vertical wall portion continuous from the top portion, and a concave curved portion curved in a concave shape in a top view, the method comprising: performing press-forming method according to  claim 2 . 
     
     
         6 . The method of manufacturing a press-formed product according to  claim 4 , wherein the press-forming is performed in the intermediate shape forming step such that a radius of curvature R E  at an end portion of the curve of the concave curved portion having the intermediate shape is set to be larger than a radius of curvature R 0  at the concave curved portion having the target shape. 
     
     
         7 . The method of manufacturing a press-formed product according to  claim 5 , wherein the press-forming is performed in the intermediate shape forming step such that a radius of curvature R E  at an end portion of the curve of the concave curved portion having the intermediate shape is set to be larger than a radius of curvature R 0  at the concave curved portion having the target shape. 
     
     
         8 . The press-forming method according to  claim 2 , wherein, in the intermediate shape forming step, a radius of curvature R E  at an end portion of the curve of the concave curved portion having the intermediate shape is set to be larger than a radius of curvature R 0  at the concave curved portion having the target shape.