Press forming method and press forming apparatus for automotive outer panel

A press forming method for an automotive outer panel, press forming a metal sheet into the automotive outer panel having a character line and panel surface portions continuous on both. sides of the character line using a punch, a die facing the punch and a blank holder facing an end of the die, wherein

• the die includes an elastic body that
• protrudes toward the punch than a die-side forming surface portion so that the elastic body is able to contact and press a position away from a portion corresponding to the character line in the metal sheet, along the portion corresponding to the character line, and
• is supported to be contractable until a contact surface portion in contact with the metal sheet is flush with the die-side forming surface portion,
• the press forming method comprising:
• an elastic body contact step of moving the die relative to the punch side while both ends of the metal sheet are sandwiched between the die and the blank holder, to bring the contact surface portion of the elastic body into contact with the metal sheet before a portion of the metal sheet in contact with the punch is plastically deformed;
• and
• a press forming step of further moving the die relative to the punch side up to a bottom dead center while pressing the metal sheet by the contact surface port on of the elastic body to contract the elastic body, wherein
• an amount of protrusion of the elastic body from the die-side forming surface portion is set so that
• a frictional force given by a product of a load of the elastic body pressing the metal sheet in the press forming step and a friction coefficient of the elastic body and the metal sheet, is equal to or greater than an absolute value of a difference between tensions acting on both sides sandwiching the portion corresponding to the character line.