Patent ID: 7454942

Claim:
Method for production of a hollow molded part made of a metallic material and having a shape of an A-column of a motor vehicle and produced out of a tubular starting part (A) having a starting outer diameter (D 1 ) and a starting wall thickness (b 1 ), characterized in that initially the tubular starting part (A) maintains a first cylindrical region ( 1 ) and is reduced by a radial or tangential deformation method in at least a second region ( 2 ) conically with an angle (α) and in at least a third region ( 3 ) cylindrically to a smaller diameter (D 2 ) and thereby forming a mold blank (V) having an increased wall thickness (b 2 ) relative to the starting wall thickness (b 1 ) in the second region ( 2 ) and in the third region ( 3 ); then bending the mold blank (V) in the second region ( 2 ) according to a required curvature for thereby forming an A-column; performing a final forming of the A-column by inner high pressure metal forming of the mold blank (V) in the first region and/or in the second region; maintaining a cylindrical form of the first cylindrical region; and accepting large loads in a crash case of the motor vehicle based on increased wall thickness of the A-column in the tapered central portion ( 2 ) and based on a single piece construction of the A-column.