A HOT PRESS FORMING APPARATUS AND A METHOD FOR HOT PRESS FORMING A BLANK

A method for a hot press forming apparatus and a hot press forming apparatus (102; 202) for forming a blank (104), the hot press forming apparatus (102; 202) comprising a first die (106; 206) and a second die (108), wherein the first die (106; 206) has at least one die cavity (110; 210), and the second die (108) has at least one die protrusion (112), wherein the hot press forming apparatus (102; 202) is configured to, by means of the first and second dies (106, 108; 206, 108), press form the blank (104) placed between the first and second dies (106, 108; 206, 108). At least one of the first and second dies (106, 108; 206, 108) has a draw radius (116; 216), wherein a member (118; 218) is attached to a die (106; 206) which has a draw radius (116; 216). At least a portion (119; 219) of the member (118; 218) is positioned adjacent to or on the draw radius (116; 216). The member (118; 218) defines a first press forming surface (120; 220), and the die (106; 206) holding the member (118; 218) defines a second press forming surface (122; 222) outside the first press forming surface (120; 220). The member (118; 218) and the die (106; 206), which holds the member (118; 218), are configured such that during the same hot press forming, a first friction arises between the blank (104) and the first press forming surface (120; 220) when the blank (104) is in contact with the member (118; 218) and a second friction arises between the blank (104) and the second press forming surface (122; 222) when the blank (104) is in contact with the die (106; 206) which holds the member (118; 218), the first friction being lower than the second friction. L'invention porte sur un procédé pour un appareil de formage par pressage à chaud et sur un appareil de formage par pressage à chaud (102 ; 202) pour la formation d'une ébauche (104), l'appareil de formage par pressage à chaud (102 ; 202) comprenant une première matrice (106 ; 206) et une seconde matrice (108), la première matrice (106 ; 206) comportant au moins une cavité de matrice (110 ; 210), et la seconde matrice (108) comportant au moins une saillie de matrice (112), l'appareil de formage par pressage à chaud (102 ; 202) étant conçu pour, au moyen des première et seconde matrices (106, 108 ; 206, 108), former par pressage l'ébauche (104) placée entre les première et seconde matrices (106, 108 ; 206, 108). Au moins l'une des première et seconde matrices (106, 108 ; 206, 108) présente un rayon d'emboutissage (116 ; 216), un élément