Method, device, and program of designing press forming die, and method of manufacturing press formed part
A designing method of a press forming die reduces a press forming load and includes: making a die model in which a surface of the press forming die is provided with a virtual thickness by a nonrigid two-dimensional element; setting stiffness distributions of the die model by making a boundary condition of the two-dimensional element vary depending on a portion of the die model; acquiring a press forming load by performing a press forming analysis by using the die model in which the stiffness distributions are set; determining whether the press forming load is within a predetermined range of the press forming load; determining the set stiffness distributions of the die model as design stiffness distributions of the press forming die in a case where it is determined that the press forming load is within the predetermined range of the press forming load.
1 . A manufacturing method of a press forming die, comprising:
a die model making step of making a die model in which a surface of the press forming die is provided with a virtual thickness by a nonrigid two-dimensional element;
a die model stiffness distribution setting step of setting stiffness distributions of the die model by making a boundary condition of the two-dimensional element vary depending on a portion of the die model;
a press forming load acquiring step of acquiring a press forming load by performing a press forming analysis by using the die model in which the stiffness distributions are set;
a press forming load determining step of determining whether the press forming load is within a predetermined range of the press forming load; and
a press forming die design stiffness determining step of
determining the set stiffness distributions of the die model as design stiffness distributions of the press forming die in a case where it is determined in the press forming load determining step that the press forming load is within the predetermined range of the press forming load; and
changing the stiffness distributions of the die model in the die model stiffness distribution setting step and repeating the press forming load acquiring step and the press forming load determining step until the press forming load falls within the predetermined range of the press forming load in a case where it is determined in the press forming load determining step that the predetermined range of the press forming load is not within the predetermined range of the press forming load, and determining the changed stiffness distributions of the die model as the design stiffness distributions of the press forming die when the press forming load falls within the predetermined range of the press forming load; and
a press forming die design stiffness distributions acquiring step of acquiring the design stiffness distributions of a press forming die;
a press forming die manufacturing step of manufacturing a real press-forming die based on the acquired design stiffness distributions of the press forming die; and
a press forming step of performing press forming by using the real press-forming die.
2 . The manufacturing method of a press forming die according to claim 1 , wherein the boundary condition in the die model stiffness distribution setting step is any one or combination of: displacement restraint; Young's modulus; a sheet thickness; density; mass; and yield strength.
3 . The manufacturing method of a press forming die according to claim 1 , wherein the nonrigid two-dimensional element is an elastic or elasto-plastic two-dimensional element.
4 . The manufacturing method of a press forming die according to claim 2 , wherein the nonrigid two-dimensional element is an elastic or elasto-plastic two-dimensional element.